Abstract: Some fish colormod ification can occur under stress conditions, environment background color, health status, fish reproductive period, along with social class.The skin color of tilap ia adapted to background color under normal conditions and social stress cond itions, as well as skin colorm odifications response rate during colorm odificat ion period, were invest-igated by fish color quant ifying techno logy based on computer v ision.The results showed that skin colorm odification of tilap ia had adapted white background happened in the first 10swhile putting tilapia into the aquarium with black background, and the lightness level of the skin color had much s ign ificantmod ification(**p**p*p**p*p< 0105).