In the present study,the effects of several frequently-used cell culture media (L-15,2×L-15,3×L-15,M199 and RMPI-1640) on cell morphology and viability of hemocytes from the mitten crab,Eriocheir sinensis were studied,in order to screen an optimum culture medium for crab hemocytes.Furthermore,different proportions of fetal bovine serum (FBS) (0%,5%,10%,and 15%) as a supplement were added into an optimum culture medium to research the effects of serum on hemocyte culture.The results showed that:3×L-15 culture medium could support the best survival of hemocytes in in vitro culture.The hemocytes remained a maximum number and intact morphology relatively,and the viability of hemocytes after 96 h culture was more than 60% in 3×L-15 medium.On the contrary,the other media did not support well of the hemocyte culture,with the viability decrease to lower than 50% and obvious cell morphology changes within 12 h.In addition,the supplement of FBS had adverse effect on cell morphology and viability.These results show that 3×L-15 medium without FBS is adequate for E.sinensis primary hemocyte culture.