Abstract:The phototaxis behavior of Propylea japonica(Thunberg)response to spectral sensitivity and light intensity were investigated.The results were as follows: (1) The spectral sensitivity response at 14 monochromatic light selected through 340nm to 605nm occurred in curve with multiple peaks, the primary peak in 340nm (ultra-violet) is the highest response rate of phototaxis (21%), the secondary in 524nm (green), and the rest in 400-440nm and 483nm in order; (2) The response rate of phototaxis is increasing as the relative intensity of light, it is showed as curves with inverse “L” shape in white light and the monochromatic light of 483nm, as an upward ladder at 524nm and a near straight line at 340nm. However, the response rate could be detected at the lowest intensity and not arrived to the summit at the strongest yet; (3) The effect of sex to response to the spectral sensitivity and intensity is not significant; (4) There was not significant photophobism response to light for the ladybird, the behavior probably derived from phototaxis or partly due to random movements. It can be concluded that both the spectrum and intensity of light stimulus gave rise to the phototaxis of P. japonica, it seemed to play a more important role that the light intensity than spectrum, but the effect level was also involved with wavelengths. Moreover, a broader range of light intensity could be perceived by the ladybird compound eye.