In order to investigate the anthesis changes of potted lotus under different mass concentrations of exogenous IAA,the lotus variety sapphire was used as the experimental material，and the lotus flowers with the same growth were selected for auxin injection and wound application.The IAA mass concentration was set as follows: 0(CK,injected with distilled water of the same volume) ,100,150 and 200 mg/L were used to analyze the changes in SOD,POD,CAT activities and malondialdehyde(MDA) content of each treatment,and to analyze the correlation between the physiological indicators of resistance.The results showed that exogenous auxin stress increased the length,width and maximum diameter of lotus petals to different degrees,and the ornamental effect was better.The treatment with 150 mg/L IAA advanced the initial flowering period by 2 d,and extended the single flower life of lotus.The maximum values of SOD,POD and CAT activities in 150 mg/L IAA treatment were significantly higher than those in the control group by 10.15%,58.70%,13.40%.With the increase of treatment time,the MDA content continued to rise,and the accumulation of 150 mg/L IAA treatment was lower than that of the control at each period,while changes of the other treatments were not obvious.At flower-wilting stage,SOD activity and POD,CAT activities showed very significantly positive correlation,POD activity and CAT activity showed significantly positive correlation,and the three showed a significantly negative correlation with MDA content， respectively， indicated that when lotus suffered exogenous stress,a variety of protective enzymes interacted,prevented membrane lipid peroxidation，slowed down aging of plant cells，and extended flowering period.In summary,150 mg/L IAA treatment made lotus flower have better flower quality and significantly improved the physiological activity of various protective enzymes,slowed down the accumulation of reactive oxygen species and extended the ornamental period of lotus flower.