Abstract: Cheese ripening is a key process to form the texture and flavor of the cheese.Lactobacillus helveticus SMN2-1 isolated from Inner Mongolia traditional dairy product,was used in the production of Cheddar cheese as non-fermentative lactic acid bacteria.The effect on the quality of Cheddar cheese of Lactobacillus helveticus was studied. Results indicated that it was not obvious difference in protein,fat,moisture,and salt content of two groups of Cheddar cheese during the 90 day ripening period. (p>0.05), but significantly change such as flavor, cohesiveness, chewiness and elasticity occurred in the sample of added Lactobacillus helveticus SMN2-1 on 90 d. Therefore, added Lactobacillus helveticus in Cheddar cheese was more effectively promote protein decomposition and cheese ripening,while improving the flavor of cheese.