Abstract: 2-[2-(4-methoxy-3,5-dimethyl) pyridlmethylthio]-5-methoxyimidazo [4,5-b] pyridine was prepared with 2-chloromethyl-4-methoxy-3,5-dimethyl pyridine hydrochloride (2) and 2-mercapto-5-methoxyimidazo[4,5-b]pyridine (3) in the solution of sodium hydroxide at 30癈,the yield reached 90.1%. Subsequently, the oxidation of sulfide (3) with hydrogen peroxide of the massfraction of 30% afforded the target compound (1), tenatoprazole. The yield reached 86.3% .The overall yield reached 77.8 %.The structure of the product was characterized by IR, 1HNMR,proved the structure of the product was correct .