Formulated diet, traditional diet and their mixture are three common feeding modes for the culture of juvenile Chinese Mitten Crab (Eriocheir sinensis), but their effects on crab seed quality are unclear. Therefore, this study was conducted to compare and evaluate the effects of three feeding modes on the early culture performance, immunity and the mortality during the pathogen challenge test for the juvenile crabs. The non-special immune indices include alkaline phosphatase, acid phosphatase, γ-glutamyl transferase, total antioxidant capacity, superoxyde dismutase, phenoloxidase, peroxidase, malondialdehyde, nitric oxide, glutathione peroxidase, glutathione reductase and hemocyanin. The poison test used the strain of Aeromnas hvdrophilia Y-2-L-1 whose virulence is strong. The results showed that: (1) In both males and females, formulated diets treatment caused a shorter period of first molting than traditional diets treatment and mixture diets treatment, and significant higher weight gain rate and specific growth rate (P < 0.05) (Table 3); (2) In terms of the non-specific immune indices in the hepatopancreas, although formulated diets treatment cuased higher activity of γ-glutamyl transferase, total antioxidant capacity and superoxyde dismutase than traditional diets treatment and mixture diets treatment, the only significant difference was found in γ-glutamyl transferase; however the traditional diets treatment caused higher acid phosphatase, malondialdehyde, nitric oxide and peroxidase activities than the other two treatments, while the significant differences were found in acid phosphatase and nitric oxide for both males and females (Table 4); (3) In terms of the non-specific immune indexes in hemolymph, formulated diets treatment group had higher glutathione peroxidase and total antioxidant capacity activities than the traditional diets treatment and mixture diets treatment while traditional diets treatment group had higher alkaline phosphatase, acid phosphatase, malondialdehyde and hemocyanin than other two treatments; among these indices, significant difference was found only in malondialdehyde (Table 5); (4) During the pathogen challenge test within 12﹣96 h, traditional diets treatment group had higher cumulative mortality than the other two groups in both males and females; similar cumulative mortality was detected for the males of formulated diets treatment and mixture diets treatment while the cumulative mortality of mixture diets treatment females ranged between formulated diets treatment and traditional diets treatment (Fig. 1). In conclusion, feeding of formulated diets can improve early culture performance, immunity and survival during the pathogen challenge test of juvenile Chinese Mitten Crab, suggesting that our optimized formulated diets could improve the quality of crab seeds for Chinese Mitten Crab.