Abstract: 【Objective】 To confirm the control effect on the mixture of Pyroxasulfone and Pendimethalin to broadleaf weeds in cotton field. 【Methods】 Field trials were set up with mixture of 40% Pyroxasulfone SC and 330 g/L Pendimethalin EC to evaluate its safety to cotton and control effect on broadleaf weeds, such as Solanum nigrum, Chenopodium glaucum, Amaranthus retroflexus, Portulaca oleracea, Abutilon theophrasti. 【Results】 The results showed that germination rate of cotton was 80.56%-83.61% in treatment of mixed herbicides, there were no significant differences between treatment and contrast. The dosage of 330 g a.i./L Pendimethalin EC 742.5 g a.i./hm² were mixed with Pyroxasulfone SC 120, 180 and 240 g a.i./hm² respectively, and their control effects of plant to broadleaf weeds were 89.15%, 92.03% and 97.83% after 30 days and 87.94%, 91.49% and 95.56% after 45 days, the control effects of fresh weigh to broadleaf weeds were 90.80%, 93.16% and 95.65% respectively, the compound-dose treatments were more efficient than single-dose treatments on control effects of plant and fresh weight to broadleaf weeds. The yield of each treatment increased 9.89%-16.45% compared with control. 【Conclusion】 40% Pyroxasulfone SC 120-180g a.i./hm² mixed with 330 g/L Pendimethalin EC are effective to control broadleaf weeds in cotton filed and safe to cotton.