Abstract: In order to study the combined influence of pesticides and heavy metals on tobacco growth and photosynthetic performance, we conducted a pot experiment to investigate the response of tobacco growth and photosynthetic performance systematically under the single and combined pollution conditions by using metalaxyl and cadmium. The results indicated that, the single addition of 20 mg/kg metalaxyl had an inhibition effect on tobacco root biomass, chlorophyll and carotenoid contents and main photosynthetic parameters (net photosynthetic rate, stomatal conductance and transpiration rate), but it could promote tobacco height significantly at the early stage. The single addition of 20 mg/kg cadmium had different degrees of inhibition on main botanical characters, total biomass, content of photosynthetic pigment, and main photosynthetic parameters of tobacco. Under the combined pollution conditions, the two pollutants inhibited the total biomass and main photosynthetic parameters significantly at the whole growth period, and showed synergistic effect. But they inhibited the contents of chlorophyll and carotenoid differently, having synergistic effect at the early stage and antagonistic effect at the late stage of tobacco growth. Furthermore, the inhibition effect of cadmium addition on tobacco biomass, chlorophyll and carotenoid content and photosynthetic parameters was stronger than that of metalaxyl addition, which might be attributed to the degradation and metabolization of metalaxyl in tobacco field. In summary, the ecological toxic effects of combined pollution of metalaxyl and cadmium on tobacco growth and photosynthetic performance changed with the tobacco growth stages.