Abstract: Taking radish as test material, the pot experiment were conducted to study the effects of exogenous selenium(0.5 mg·kg^-1 and 1.0 mg·kg^-1) on photosynthetic pigment content and selenium and cadmium absorption and transport in radish under cadmium stress with different concentration(5 mg·kg^-1 and 30 mg·kg^-1),in order to provide reference for the best concentration of exogenous selenium on alleviate toxic effect of cadmium（Cd） on plants.The results showed that with the increase of cadmium concentration, the contents of chlorophyll a and carotenoid decreased, the contents of cadmium significantly increased in aboveground and underground parts of radish, while the contents of selenium decreased, so that the transport coefficient of cadmium and selenium increased gradually.With the increase of selenium concentration, the contents of chlorophyll a and chlorophyll b gradually increased, but the effect on carotenoids was not significant.The cadmium content in aboveground and underground parts gradually decreased, while the selenium content gradually increased, so that the transport coefficient of cadmium and selenium gradually increased.Under selenium-cadmium interaction, the contents of chlorophyll a and carotenoid in radish significantly increased compared with the control, and the contents of selenium in aboveground and underground parts of radish significantly increased compared with the control, and the content of cadmium and the transfer coefficient of cadmium increased when 0.5 mg·kg^-1 selenium was applied compared with the single cadmium treatment.The interaction between exogenous selenium and 5 mg·kg^-1 cadmium increased the selenium transport coefficient, while the interaction between exogenous selenium and 30 mg·kg^-1 cadmium significantly reduced the selenium transport coefficient.The results showed that the two selenium concentrations within the experimental concentration range had certain alleviating effect on radish under cadmium stress, but 0.5 mg·kg^-1 selenium had the best alleviating effect on radish under cadmium stress(5 mg·kg^-1).