In this study, the responses of turbots to crowding stress were studied though obverting the changes of immune and stress index in blood, spleen, head kidney, gills and skin before and after being inoculated with attenuated Edwardsiella tarda vaccine, using turbots cultured in different initial stocking densities (low density: 5 kg/m2, medium density: 10 kg/m2, high density: 20 kg/m2). The results showed that: the immune indexes such as serum interleukin (1L-1β), complement (C3), immunoglobulin M (IgM), lysozyme (LZM) and tumor necrosis factor (TNF-α) of turbots in the low density group were significantly higher than those of the medium and high density groups (P＜0.05); the blood cortisol level of turbots in the low density group was significantly higher than that of the medium and low density groups (P＜0.05); heat shock protein (HSP70) gene expression in the high density turbots was significantly higher than that of the medium and low density groups; and, immunoglobulin M (IgM) expression in low density turbots was higher than that of the medium and high density groups. Above all, in order to improve the immune effect and reduce stress response of turbot, it is suggested to adopt low density (5 kg/m2) breeding system.