diff --git a/MakefileInst b/MakefileInst
new file mode 100644
index 0000000..0e82e6f
--- /dev/null
+++ b/MakefileInst
@@ -0,0 +1,15 @@
+OBJS=emul_inst_exec.o emul_inst_decipher.o
+CC=gcc
+PROGRAM=emulexec
+
+.SUFFIXES: .c .o
+
+$(PROGRAM): $(OBJS)
+	$(CC) -o $(PROGRAM) $^
+
+.c.o:
+	$(CC) -c $<
+
+.PHONY: clean
+clean:
+	rm -f $(OBJS) $(PROGRAM)
diff --git a/emul.c b/emul.c
index 98298c4..6af6ce9 100644
--- a/emul.c
+++ b/emul.c
@@ -4,12 +4,5 @@
 
 int main(void) {
     emul_reg_init();
-    emul_open_file("test.txt", "w+");
-    emul_out_file('a');
-    emul_out_file('a');
-    emul_out_file('a');
-    emul_out_file('a');
-    emul_out_file('a');
-    emul_out_file('a');
-    emul_close_file();
+
 }
diff --git a/emul_inst_decipher.c b/emul_inst_decipher.c
index 5b238d6..c9745a4 100644
--- a/emul_inst_decipher.c
+++ b/emul_inst_decipher.c
@@ -1,5 +1,6 @@
 #include "emul_inst_decipher.h"
 #include <stdio.h>
+#include <ctype.h>
 
 /*
 typedef struct {
@@ -8,50 +9,120 @@
 } emul_isa_t;
 */
 
-emul_isa_t isa_dict[] {
-    { ADD, "add" },
+#define ISA_COUNT 23
+emul_isa_t isa_dict[ISA_COUNT] = {
+    { ADD , "add"  },
     { ADDI, "addi" },
-    { SUB, "sub" },
-
-    { SLT, "slt" },
+    { SUB , "sub"  },
+    { SLT , "slt"  },
     { SLTI, "slti" },
-    { SEQ, "seq" },
-    { SGE, "sge" },
-    { SGT, "sgt" },
-    { SLE, "sle"},
-    { SNE, "sne" },
-
-    { B, "b"},
-    { BEQ, "beq" },
-    { BNE, "bne" },
-    { J, "j" },
-
-    { LW, "lw" },
-
-    { SW, "sw" },
-
+    { SEQ , "seq"  },
+    { SGE , "sge"  },
+    { SGT , "sgt"  },
+    { SLE , "sle"  },
+    { SNE , "sne"  },
+    { B   , "b"    },
+    { BEQ , "beq"  },
+    { BNE , "bne"  },
+    { J   , "j"    },
+    { LW  , "lw"   },
+    { SW  , "sw"   },
     { MOVE, "move" }
 };
 
-FILE *fp;
+#define REG_COUNT 30
+emul_reg_t reg_dict[REG_COUNT] = {
+    { Szero, "$zero" },   // Zero register
+    { Sat  , "$at"   },   // using asem
+    { Sv0  , "$v0"   },   // return
+    { Sv1  , "$v1"   },
+    { Sa0  , "$a0"   },   // argment
+    { Sa1  , "$a1"   },
+    { Sa2  , "$a2"   },
+    { Sa3  , "$a3"   },
+    { St0  , "$t0"   },   // temp
+    { St1  , "$t1"   },
+    { St2  , "$t2"   },
+    { St3  , "$t3"   },
+    { St4  , "$t4"   },
+    { St5  , "$t5"   },
+    { St6  , "$t6"   },
+    { St7  , "$t7"   },
+    { Ss0  , "$s0"   },   // var
+    { Ss1  , "$s1"   },
+    { Ss2  , "$s2"   },
+    { Ss3  , "$s3"   },
+    { Ss4  , "$s4"   },
+    { Ss5  , "$s5"   },
+    { Ss6  , "$s6"   },
+    { Ss7  , "$s7"   },
+    { Sk0  , "$k0"   },   // kernel
+    { Sk1  , "$k1"   },
+    { Sgp  , "$gp"   },   // grobal
+    { Ssp  , "$sp"   },   // stack
+    { Sfp  , "$fp"   },   // frame
+    { Sra  , "$ra"   }    // return address
+};
+
+static FILE *fp;
 
 void emul_inst_dec_init() {
 }
 
-void emul_inst_dec_load(char *filename) {
-    if ((fp = open(filename_cache, "r")) == NULL) {
-	fprintf(stderr, "%s is can not open", filename);
+int emul_inst_dec_load(char *filename) {
+    if ((fp = fopen(filename, "r")) == NULL) {
+	fprintf(stderr, "%s is can not open\n", filename);
+	return 0;
     }
+    return 1;
 }
 void emul_inst_dec_close() {
     fclose(fp);
 }
 
+int emul_inst_dec_get_token(char *token) {
+    static char line[LOAD_LINE_MAX] = "";
+    static char *current = line;
+    int fShift;
+    int i;
+
+    do {
+	fShift = 0;
+	// 読み込んだ行の先頭が印字可能文字になるようにシフト
+	while ( *current != '\0' && isspace(*current) ) current++;
+
+	// 読み込みを開始する先頭がヌルなら新しい行を読み込む
+	if ( *current == '\0' ) {
+	    // 読み込める行がない場合終了
+	    if ( fgets(line, LOAD_LINE_MAX, fp) == NULL) return 0;
+	    // currentにセット
+	    current = line;
+	    // 読み込み下場合はシフトフラグをセット
+	    fShift = 1;
+	}
+    } while(fShift);	// 新しい行を読み込んだ場合もう一度シフトを行う
+
+    // 次のスペース(もしくは'\0')が現れるまで読み込み
+    i = 0;
+    while ( !isspace(*current) ) {
+	token[i] = *current;
+	i++, current++;	// インクリメントに注意する
+    }
+    token[i] = '\0';
+    return 1;
+}
+
 // Example:
 //   ASM: add St0, Ss0, Ss1
 //   RETURN: add
-int emul_inst_dec_get_opecode() {
-
+int emul_inst_dec_get_opecode(char *op) {
+    int i;
+    for (i = 0; i < ISA_COUNT; i++) {
+	if ( strcmp(isa_dict[i].string, op) == 0 ) {
+	    return isa_dict[i].opecode;
+	}
+    }
+    return OPECODE_DECODE_ERROR;
 }
 
 // Example:
@@ -59,5 +130,25 @@
 //   RETURN: St0
 //   RETURN: Ss0
 //   RETURN: Ss1
-int emul_inst_dec_get_operand() {
+int emul_inst_dec_get_operand(char *op) {
+    int i;
+    for (i = 0; i < REG_COUNT; i++) {
+	if ( strcmp(reg_dict[i].string, op) == 0 ) {
+	    return reg_dict[i].operand;
+	}
+    }
+    return OPERAND_DECODE_ERROR;
+}
+
+
+int emul_inst_dec_get_next_opecode() {
+    char token[LOAD_TOKEN_MAX];
+    emul_inst_dec_get_token(token);
+    return emul_inst_dec_get_opecode(token);
+}
+
+int emul_inst_dec_get_next_operand() {
+    char token[LOAD_TOKEN_MAX];
+    emul_inst_dec_get_token(token);
+    return emul_inst_dec_get_operand(token);
 }
diff --git a/emul_inst_decipher.h b/emul_inst_decipher.h
index d34621d..b09568b 100644
--- a/emul_inst_decipher.h
+++ b/emul_inst_decipher.h
@@ -1,30 +1,44 @@
 #ifndef EMUL_INST_DECIPHER__
-#ifndef EMUL_INST_DECIPHER__
+#define EMUL_INST_DECIPHER__
 
 #include "emul_inst_isa.h"
-#include "emul_io_file"
+#include "emul_reg.h"
+
+#define LOAD_LINE_MAX 1024
+#define LOAD_TOKEN_MAX 32
 
 typedef struct {
-    int opecode;
-    int string;
+    EMUL_ISA opecode;
+    char string[32];
 } emul_isa_t;
 
+typedef struct {
+    EMUL_REG operand;
+    char string[32];
+} emul_reg_t;
+
 void emul_inst_dec_init();
 
-void emul_inst_dec_load(char *filename);
+int emul_inst_dec_load(char *filename);
 
 void emul_inst_dec_close();
 
+int emul_inst_dec_get_token(char *token);
+
 // Example:
 //   ASM: add St0, Ss0, Ss1
 //   RETURN: add
-int emul_inst_dec_get_opecode();
+int emul_inst_dec_get_opecode(char *);
+
+int emul_inst_dec_get_next_opecode();
 
 // Example:
 //   ASM: add St0, Ss0, Ss1
 //   RETURN: St0
 //   RETURN: Ss0
 //   RETURN: Ss1
-int emul_inst_dec_get_operand();
+int emul_inst_dec_get_operand(char *);
+
+int emul_inst_dec_get_next_operand();
 
 #endif
diff --git a/emul_inst_exec.c b/emul_inst_exec.c
new file mode 100644
index 0000000..4c55829
--- /dev/null
+++ b/emul_inst_exec.c
@@ -0,0 +1,114 @@
+#include "emul_inst_exec.h"
+#include <stdio.h>
+
+int emul_inst_exec_loadfile(char *filename) {
+    return emul_inst_dec_load(filename);
+}
+
+void emul_inst_exec_closefile() {
+    emul_inst_dec_close();
+}
+
+/* オペコード解読処理群 - START */
+void emul_inst_exec_add(int r0, int r1, int r2) {
+    printf("Execute: add r0[%d], r1[%d], r2[%d];\n", r0, r1, r2);
+}
+
+void emul_inst_exec_sub(int r0, int r1, int r2) {
+    printf("Execute: sub r0[%d], r1[%d], r2[%d];\n", r0, r1, r2);
+}
+/* オペコード解読処理群 - END */
+
+/* Execute Step
+ * RETURN:
+ *   seccsess: 1
+ *   failed  : 0 */
+int emul_inst_exec_step()
+#define COUNT_OPERAND_MAX 3
+{
+    char token[LOAD_TOKEN_MAX];
+    int op_id, oprs[COUNT_OPERAND_MAX];
+
+    // トークンを取得
+    emul_inst_dec_get_token(token);
+    // オペコードIDを取得
+    op_id = emul_inst_dec_get_opecode(token);
+
+    // 例外処理: オペコードが見つからない
+    if ( op_id == OPECODE_DECODE_ERROR ) {
+	printf("Non exist next operand\n");
+	return 0;
+    }
+
+    // オペコード実行
+    switch (op_id) {
+	case ADD :
+	    emul_inst_exec_add(
+	        emul_inst_dec_get_next_operand(),
+	        emul_inst_dec_get_next_operand(),
+	        emul_inst_dec_get_next_operand()
+	    );
+	    break;
+	//case ADDI:
+	//    break;
+	case SUB :
+	    emul_inst_exec_sub(
+	        emul_inst_dec_get_next_operand(),
+	        emul_inst_dec_get_next_operand(),
+	        emul_inst_dec_get_next_operand()
+	    );
+	    break;
+	//case SLT :
+	//    break;
+	//case SLTI:
+	//    break;
+	//case SEQ :
+	//    break;
+        //case SGE :
+	//    break;
+        //case SGT :
+	//    break;
+        //case SLE :
+	//    break;
+        //case SNE :
+	//    break;
+	//case B   :
+	//    break;
+	//case BEQ :
+	//    break;
+	//case BNE :
+	//    break;
+	//case J   :
+	//    break;
+	//case LW  :
+	//    break;
+	//case SW  :
+	//    break;
+	//case MOVE:
+	//    break;
+	default:
+	    printf("まだ実装してないので待って！\n");
+    }
+    //emul_inst_dec_get_operand(token);
+
+    return 1;
+}
+
+/* Execute Run All
+ * RETURN:
+ *   seccsess: 1
+ *   failed  : 0 */
+int emul_inst_exec_run() {
+    // step関数を終わるまで呼び出せばよい
+    return ;
+}
+
+int main(void) {
+    emul_inst_exec_loadfile("test.asm");
+    while ( emul_inst_exec_step() ) {
+	puts("...Wait for step, please input key enter.");
+	getchar();
+    }
+    emul_inst_exec_closefile();
+    return 0;
+}
diff --git a/emul_inst_exec.h b/emul_inst_exec.h
new file mode 100644
index 0000000..b9acf03
--- /dev/null
+++ b/emul_inst_exec.h
@@ -0,0 +1,21 @@
+#ifndef EMUL_INST_EXEC__
+#define EMUL_INST_EXEC__
+
+#include "emul_inst_decipher.h"
+
+int emul_inst_exec_loadfile(char*);
+void emul_inst_exec_closefile();
+
+/* Execute Step
+ * RETURN:
+ *   seccsess: 1
+ *   failed  : 0 */
+int emul_inst_exec_step();
+
+/* Execute Run All
+ * RETURN:
+ *   seccsess: 1
+ *   failed  : 0 */
+int emul_inst_exec_run();
+
+#endif
diff --git a/emul_inst_isa.h b/emul_inst_isa.h
index 3bd115b..ec57cb0 100644
--- a/emul_inst_isa.h
+++ b/emul_inst_isa.h
@@ -1,7 +1,11 @@
 #ifndef EMUL_INST_ISA__
 #define EMUL_INST_ISA__
 
-enum EMUL_ISA {
+typedef enum {
+    // 翻訳のための擬似オペコード
+    OPECODE_DECODE_ERROR,
+
+    // オペコード
     ADD,
     ADDI,
     AND,
@@ -96,7 +100,7 @@
     SYSCALL,
     BREAK,
     NOP
-}
+} EMUL_ISA;
 
 #endif
 
diff --git a/emul_reg.h b/emul_reg.h
index 5967c93..cdb6e59 100644
--- a/emul_reg.h
+++ b/emul_reg.h
@@ -1,46 +1,51 @@
 #ifndef EMUL_REG__
 #define EMUL_REG__
 
-#define Szero 0	// Zero register
+typedef enum {
+    // 翻訳のための擬似オペランド
+    OPERAND_DECODE_ERROR,
 
-#define Sat 1	// using asem
+    Szero,    // Zero register
 
-#define Sv0 2	// return
-#define Sv1 3
+    Sat,      // using asem
 
-#define Sa0 4	// argment
-#define Sa1 5
-#define Sa2 6
-#define Sa3 7
+    Sv0,      // return
+    Sv1, 
 
-#define St0 8	// temp
-#define St1 9
-#define St2 10
-#define St3 11
-#define St4 12
-#define St5 13
-#define St6 14
-#define St7 15
+    Sa0,      // argment
+    Sa1, 
+    Sa2, 
+    Sa3, 
 
-#define Ss0 16	// var
-#define Ss1 17
-#define Ss2 18
-#define Ss3 19
-#define Ss4 20
-#define Ss5 21
-#define Ss6 22
-#define Ss7 23
+    St0,      // temp
+    St1, 
+    St2, 
+    St3, 
+    St4, 
+    St5, 
+    St6, 
+    St7, 
 
-#define Sk0 26	// kernel
-#define Sk1 27
+    Ss0,      // var
+    Ss1, 
+    Ss2, 
+    Ss3, 
+    Ss4, 
+    Ss5, 
+    Ss6, 
+    Ss7, 
 
-#define Sgp 28	// grobal
+    Sk0,      // kernel
+    Sk1, 
 
-#define Ssp 29	// stack
+    Sgp,      // grobal
 
-#define Sfp 30	// frame
+    Ssp,      // stack
 
-#define Sra 31	// return address
+    Sfp,      // frame
+
+    Sra      // return address
+} EMUL_REG;
 
 
 int reg[32];
diff --git a/test_asm/test.asm b/test_asm/test.asm
new file mode 100644
index 0000000..d4fc288
--- /dev/null
+++ b/test_asm/test.asm
@@ -0,0 +1,2 @@
+add $t0 $s0 $s1
+sub $s4 $t0 $s3