Abstract: In order to study the effects of topramezone on common weed control in corn and the sensitivity of different sweet corn cultivars to topramezone, 16 kinds of sweet corn cultivars were treated by 25.00 g/hm2 topramezone at 4-6 leaf stage, the effect of weed control and the inhibition rate of plant height were calculated. The results showed that, topramezone provided a control of 90% on common weeds; effects of topramezone on sweet corn seedling growth could have some phytotoxicity injury, the inhibition rate of plant height to ‘Zhongtian No.8’ and ‘Zhengtian 68’ were 24.83% and 23.01% at 10 days after application, they are more sensitive than other; the sugar content of sweet corn has no correlation with sensitivity to topramezone.