Experiment on control spectrum of several herbicides of post-emergence of corn was car-ried out in pot-cultured and in open field..The results showed that the weed control spectrum of nicosul-furon,2,4-D butylate and atrazine are different.Therefore,the mixture of nicosulfuron+2,4-D butylate,nicosulfuron+atrazine can enlarge the range of weeds controlling.Field experiment was conducted to fur-ther evaluate joint action of nicosulfuron+2,4-D butylate,nicosulfuron+atrazine.The results showed that the control effect of 30 days after spraying of 4% nicosulfuron SC50 mL/667m²+72% 2,4-D butylate EC 25 mL/667m²,4% nicosulfuron SC 75 mL/667m²+72% 2,4-D butylate EC30 mL/667m²,4% nicosul-furon SC 50 mL/667m²+38% atrazine SC 100 mL/667m²,4% nicosulfuron SC 75 mL/667m²+38% a-trazine SC 150 mL/667m² to granineous weeds were 94.06%,97.83%,94.84% and 98.12%,and they were 92.49%,97.35%,92.62% and 97.20% to broadleaf weeds.