Colletotrichum capsici is one of the main pathomycete to the postharvest of pepper and destroying the quality shortens its storage period. The effects of storage at (28±1)°C and (90±5)% relative humidity on the metabolism of reactive oxygen species (ROS) in pepper were investigated by using green round pepper as the experimental material， scratching inoculated with C. capsici as the treatment group and scratching inoculated with sterile water as the control. The results showed that compared with the control group， the disease index of pepper inoculated with Colletotrichum capsici was significantly increased， and the disease index was as high as 3.97 (P<0.05) at 9 d. The cell membrane permeability， MDA content， total phenol and flavonoid accumulation of pepper after infection with C. capsici were 1.44， 5， 1.26， 1.24 times of the control group， respectively. The 'oxidative burst'--H2O₂ content and O₂- production rate increased in the early stage of storage， and the infection of C. capsici promoted the activities of PPO， POD， SOD and APX in pepper， and by 9 d of storage， the activities of PPO， SOD and APX were 22， 1.09 and 1.67 times higher than those of the control group， respectively. The activities of CAT and PAL increased first and then decreased， and PAL reached the peak on the 5th day， which was 1.506 times that of the control. Correlation analysis showed that O₂- production rate， PPO， POD， SOD and APX activities were significantly positively correlated with disease index (P<0.01). Combined with principal component analysis， it can be seen that pathogen infection activates the defense system of pepper， breaks the dynamic balance of redox in pepper， leads to the increase of ROS accumulation in the later stage of storage， which in turn causes serious damage to peppers' tissues， aging and rotting. Compared with scratch treatment， the infection of pepper anthracnose makes the oxidative damage of pepper more serious. This study elucidates the relationship between C. capsici and pepper active oxygen metabolism， and provides a theoretical basis for further research on the pathogenesis of pepper anthracnose and its prevention and control measures.