The enzymatic hydrolysis of cream to natural milk flavor by lipase AY was conducted.The optimal the ratio of cream and whey powder,enzyme content and reaction tempreture were 14∶1,0.2 g/100 g cream and 45 ℃,respectively.The milk flavor had a high sensory score.GC-MS analysis showed that there were about 80% free fatty acids and 20% lactones and ketones.The natural milk flavor produced had strong cheese flavor and light sweet milk aroma.Moreover,the taste of the milk flavor could be improved by adding some whey powder.