Abstract: Whether fish species can adjust their physiological and behavioral traits well to the change of environmental condition of their habitats are key for the future fate of the local population. The aim of the present study was to investigate the physiological and behavioral responses of two endangered fish species, i.e. Chinese sucker (Myxocyprinus asiaticus) and Qingbo (Spinibarbus sinensis) subjected to short-term predation acclimation. We measured the maximum acceleration swimming speed (U_cat), spontaneous shoal behavior (percent time spent moving, median swimming speed and inter-individual distance), innate immune indicator (plasma lysosome activity), specific immune indicator (plasma IgM level), and antioxidant defense ability (plasma SOD activity) of either predation acclimated (reared with snakehead, Channa argus without direct contact) or non-acclimated (as control) juveniles of Chinese sucker and Qingbo for a period of 1 week. The plasma cortisol level and spontaneous activity were measured under both predator present and predator absent conditions. The main results of this study are as follows: (1) Qingbo showed stronger swimming capacity, more active spontaneous behavior, higher plasma cortisol and IgM levels as well as more profound response of both plasma cortisol and IgM level to predation acclimation, compared to those of Chinese sucker. (2) predation acclimation elicited higher plasma cortisol and IgM levels and higher plasma lysosome activity, especially in Qingbo. (3) acute predator exposure resulted in higher plasma cortisol and shorter inter-individual distance whereas the later only manifested in non-acclimated groups. In conclusion, both non-specific and specific immune function up-regulated after predation acclimation possible via the increased release of cortisol which might evolved with purpose to a fast recovery after possible non-lethal hunting. These adjustments indicated that predation training might act as a potential training process for fisheries releasing in the Yangtze River water system. The distinct difference in behavior, immune system and their response to predation acclimation or acute predator exposure suggested that these two fish species might have different fate in near future due to the unpredictable change in environmental factor such as predation.