The author carried out experiments to find out the response of rock bream, Oplegnathus fasciatus (TEMMINCK et SCHLEGEL) and sea bass, Epinephelus septemfasciatus (THUNBERG) to the color nettings. The experimental water tank(180L$ imes$50W$ imes$55Hcm) was set up n a dark room and water level was maintained 50cm high from the bottom. The tank was devided three longitudinal sections marking 60 cm interval. The illumination systems, consisted of 20 watt fluorescent lamps and filter, were suspended adove the tank. Two different color nettings selected from five colors (red, yellow, green, blue, black) were placed in each end section of the tank. Ten fish were used in each experiment and the fish were acclimatized in the dark for 60 minutes before experiment. After the light on, the number of fish in each section of the tank was counted in every 30 seconds interval for 30 minutes. The results obtained are as follows: 1. The rock bream selected the color nettings in the order of yellow, black, blue, green and red. 2. The sea bass selected the color nettings in the order of green, black, red, blue and yellow.