Abstract:The effects of pyrametostrobin on physiological indices and protective enzymes in cucumber and tomato were studied with pot tests in greenhouse. The results showed that the content of chlorophyll in cucumber and tomato leaves were promoted by pyrametostrobin significantly to the control, the effect with 300mg/L was fastest and most significant. To a certain extent, the bigger the concentration of pyrametostrobin, the higher the content of chlorophyll, while the effects on the soluble sugar and protein were not significant. The activities of protective enzymes under the treatment of pyrametostrobin with different concentrations were all increased in certain time. The activities of POD, PPO, CAT and SOD with 300mg/L were 34.67%, 34.78%, 36.36% and 11.94% higher than the control, respectively. The changes were larger and more significant with higher concentration of pyrametostrobin.