The effects of reared Daphnia magna by different diets with various lipid sources as the live food on the metamorphosis, survival and growth of the Chinese mitten crab Eriocheir sinensis during the juvenile development stages from magalopa to juvenile crab four(C4) were studied from May 20，2003 to June 22,2003. The mitten crabs with different development stages were divided into three experimental groups and fed on Daphnia magna reared by three different diets with various lipid sources, the first group fed on pure bread yeast(yeast group), the second one fed on pure bread yeast with 10% soybean oil(soybean group) enrichment, the third one fed on pure bread yeast with 10% fish oil enrichment (fish oil group), the water temperature during experiments is from 20-24 ℃. The results show that the juvenile crab with different development stages rearing with fish oil group food obtained the earlier metamorphosis, better survival and faster growth than those of the other two groups. The width of empty carapace of C3 (juvenile crab three) fed on fish oil group food and soybean oil group food is bigger than those of crab fed on yeast group food. The analysis of lipid content and fatty acid composition of different stages of juvenile crab with different foods group suggested that the crab fatty acid compositions reflected the corresponding dietary composition. The crab fed on fish oil group food tended to accumulate more lipid and higher composition of DHA, EPA, HUFA than those of other two group food, and crab fed on soybean oil group food tended to accumulate highest C18:2n6.The higher composition of DHA, EPA, HUFA) or C18:2n6 in the food (D. magna) results in good survival, growth and metamorphosis of the mitten crab. So the results demonstrated the importance of dietary EPA, DHA in Chinese mitten crab juvenile development stages, which shortened the critical period of metamorphosis timing and enhanced survival and growth. Dietary content of PUFA, probably high 18: 2n6 may also have a good result to enhance survival and metamorphosis timing and growth.