Abstract: Studies were carried out on degradation pattern s of chlorsulfuron in soils of wheat fields in Jiangsu and Hebei.The results sho wed that the degradation of chlorsulfuron in soils was very slow,with half-life being 22.82 days and 32.98 days in Jiangsu and Hebei,respectively.Rice is highl y sensitive to chlorsulfuron residue in the soil left from the preceding wheat c rop.The concentration of chlorsulfuron residue of 0.1 μg/kg is high enough to i nhibit root growth of the following rice crop.