Ring work belongs to three work of cyclohexdione herbicide ketone, mainly for the forest fire way weeds, shrubs and sugarcane annual weed control. By the end of 2008, with 5 enterprises in our country registered ring work products, including ketones reversed-phased overseas enterprise home 1, domestic enterprises four. According to the enterprise, jiangsu province division 3, anhui home 1. In 1995, jiangsu LanFeng biological chemical Co., LTD. (formerly jiangsu xinyi pesticide Co., LTD) first registration. In 1999 and 2001 respectively only American dupont and jiangsu province jiangyin KaiJiang agrichemicals Co., LTD each home 1 enterprise registration. 2008 were two enterprise registration, respectively is jiangsu wulat middle banner chemical Co., LTD and anhui zhongshan chemical Co., LTD.