Abstract: FirstRate plus different auxiliaries were studied in soybean field to research their phytocidal effect of Commelina communis Linn, Cirsium setosum, Herba Sonchi Brachyoti and the other broadleaf weeds and safety. The results showed that the every phytocidal effect of all treats on individual weeds and fresh weight were more than 60% after ten days, but it were not effective to Chenopodium album and Epuisetum arvense. Ecosurf SA-9, Triton X-100 and Tergitol L-62 were safe to soybean, but ULD-E was unsafe because there were yellow spots on leafs. After forty-five days, the phytocidal effect of all treats on individual were all low control effect, but on fresh weight of Commelina communis Linn and Cirsium setosum were that FirstRate+X-100 was more than 89.7%, 98.1%, FirstRate+SA-9 was more than 95.9%, 78.8%, FirstRate+L-62 was more than 92.5%, 97.2%, FirstRate+ ULD-E was more than 91.5%, 92.7%. The phytocidal effects of all treats on fresh weight were more than 85.2% to Herba Sonchi Brachyoti and 100% to Siberia Cocklebur and Siegesbeckia. The every phytocidal effect of all treats was better than only FirstRate treat. The every phytocidal effect of different concentration of four auxiliaries were different, the 1000 time liquid was the best than the 2000 than the 500. The phytocidal effect of four auxiliaries were Ecosurf SA-9> Triton X-100> Tergitol L-62> ULD-E.