Abstract: Aim:To analyze the effects of radiation treatment with different doses on the nutrition ingredients of milk powder. Methods:Milk powder samples was radiated by 30Coγwith 0,5,10,15 and 20kGy respectively.The main nutrition ingredients, microbiological index,and sensory characteristic were analyzed before and after radiation.Results:To contrast with control group,there is no significant difference in main nutrition ingredients and sensory characteristics after radiation of 5kGy or 10kGy, but the number of microorganism is greatly decreased.The main nutrition ingredients decrease greatly after the radiation of 15kGy or 20kGy（p＜0.05）,and there are no microorganism and no significant difference in sensory characteristics.Conclusion:The radiation of less than 10kGy is the best way to prolong the storage life and enhance the security of milk powder.

Key words: radiation, milk powder, nutrition ingredient