I investigated the impact of flow and predator stress acclimation on the swimming per- formance and predator avoidance ability of juvenile qingbo Spinibarbus sinensis. The experimental sub- jects were acclimatized for 20 d to nearly still water (control), flowing water, or nearly still water in the presence of their natural predators. Fish housed in flowing water showed a significantly greater ca pacity for prolonged swimming, as suggested by their critical swimming speeds compared to those of the other 2 groups. The group acclimatized to predators reacted more quickly to a predator stimulus, but did not exhibit faster burst (indicated by fast-start escape response) or prolonged swimming speeds. However, both the group housed in flowing water and the group exposed to predators demonstrated signifi- cantly greater predator avoidance capabilities than the control group. Therefore, both treatments sub- stantially improved predator avoidance capabilities, although, apparently, via different mechanisms. This result may have considerable importance in the de- velopment of optimal rearing conditions in hatcheries for fish that are destined to be released into the wild.