The soil cultivation experiment was used to investigate the accumulation and distribution of cobalt in broad bean(Vicia faba L.) and the effects of cobalt on the photosynthetic characteristics and antioxidant properties of broad bean leaves.Broad bean seedlings at the six-leaf stage were treated with different concentration cobalt(0,20,40,80,120 mg·kg^-1),and the cobalt content in roots,stems and leaves,photosynthetic pigment content,photosynthetic gas exchange parameters,chlorophyll fluorescence parameters of leaves,growth indexes,POD,CAT and SOD activities of leaves were investigated on the 14th day after the cobalt treatment.The results showed that:(1)the roots,stems and leaves of broad bean could absorb and accumulate a certain amount of cobalt,and there was a significant positive correlation between the cobalt content of broad bean and soil cobalt content.There were obviously differences in cobalt content between the different organs,and the order of cobalt content from high to low was roots,leaves and stems.(2)Chlorophyll a content(Chl a),chlorophyll b content(Chl b),stomatal conductance(G_s),the maximal photochemical efficiency of PSⅡ(F_v/F_m) and the potential activity of PSⅡ(F_v/F₀) took on the promoting effects on 0-40 mg·kg^-1 and the inhibitory effects on 40-120 mg·kg^-1;Net photosynthetic rate(P_n),intercellular CO₂ concentration(C_i),the minimum fluorescence of PSⅡ(F₀),the maximum fluorescence of PSⅡ(F_m) took on the promoting effects on 0-80 mg·kg^-1 and the inhibitory effects on 80-120 mg·kg^-1;Transpiration rate(T_r),carotenoid content(Car) took on the promoting effects on 0-120 mg·kg^-1,and all photosynthetic parameters in promoting maximum 40 mg·kg^-1.(3)Root length,plant height,biomass,POD,CAT and SOD activities showed a obvious rise under low concentrations of cobalt,and a decline under high concentrations of cobalt.These results showed low concentrations of cobalt could improve the photosynthesis and growth,while high concentrations of cobalt significantly inhibited the photosynthetic efficiency,growth and development of plants.