Abstract: Fluorescent ramification was formed when rimsulfuron and chlorsulfuron was irradiated by ultraviolet radiation.The photochemical fluorescence(PCF) characteristics of fluorescent ramification in various solvents and relevant influenced factors were investigated.Thus,a novel PCF analytical method was developed to determinate rimsulfuron and chlorsulfuron residues in soil.It's found that cetyltrimethylammonium chloride(CTAC) colloidal dispersion(2×10-3 mol/L),with a certain acidity or alkalinity(rimsulfuron pH 7,chlorsulfuron pH 12) and illuminating 150 s were the best conditions to determine the above two sulfonylurea herbicides by PCF method.Under the optimum experiment conditions,the limits of determination were 0.7 μg/kg and 0.6 μg/kg,respectively,with relative standard deviations of 1.7% and 2.1%,respectively.The method was successfully applied to analyze rimsulfuron and chlorsulfuron residues in three different type soil samples(i.e.,silty loam,yellowish red soil and purplish soil).The average recoveries of rimsulfuron and chlorsulfuron in three different type soil samples were 99.0%±1.0% and 98.7%±4.1%,97.6%±1.7% and 97.0%±4.7%,96.7%±2.3% and 95.4%±5.5%,respectively.It indicated that the estabolished PCF analytical method was reliable and rapid in determination of rimsulfuron and chlorsulfuron residues in soil samples.