This research first studied the kinds of weeds in rape field after rice their occurrence and succession regularity by removing them, then investigated their control efficiencies of 3 different herbicides. by means of the comparison between manual weedinf and no weeding. The results showed that 16 kinds of weeds, belonging to10 series, were found in the rape field after rice. The hydrophilous weed Poa annual was the dominant species, the subdominant weed species were Alopecurus aequalis and Stellaria media. These weeds usually started to sprout in the middle of Oct. There were one density peak and one emergence peak before winter in the rape field after rice. In spring, weed biomass increased slightly, but the weed density did not increase. After 8 days of application of 3 750 mL/hm2 of Phosphinothricin 13.5% SL in 250 kg water spraying in the period of four leaves, the control efficacies for total weeds and grass weeds and broadleaf weeds were 90%, 16 and 32 and 64 days later, they were still nearly 90%, Compared with the negative CK, rapeseed yield increased nearly 8%. with the help of herbicides of Phosphinothricin. .