Abstract: The residual dynamics and final residues of nitenpyram in water,soil,paddy and rice samples in supervised field residue trials were determined by high performance liquid chromatography equipped with ultraviolet detector (HPLC-UVD).Water samples were extracted with methylene chloride.Soil samples were extracted with water only,and paddy and rice samples firstly with water then with acetone.The extracts were cleaned up by liquid-liquid extraction,and further cleaned up by column chromatography.Under the fortified level 0.1 to 5 mg/L for water,0.1 to 5 mg/kg for soil,and 0.2 to 5 mg/kg for paddy and rice,the recovery ranged from 77.2% to 100.3% with the relative standard deviations of 1.9%-12.9%.The limit of quantification (LOQ) of the method was 0.1 mg/L for water,0.1 mg/kg for soil,0.2 mg/kg for paddy and rice.The limit of detection (LOD) of the method was 0.04 mg/L for water,0.04 mg/kg for soil,0.08 mg/kg for paddy and rice.The results of simulating dynamic test in greenhouse showed that applied at exaggerated rate of dosage (1 500 g a.i./hm2), the half-life of nitenpyram was 0.58 days in water,3.31 days in soil and 2.70 days in paddy,respectively.When sprayed for 3 and 4 times at 1.5 times of the recommended dosage (112.5 g a.i./hm2),at interval time of 7 d after the last application,the final residues of nitenpyram in rice were lower than LOD (0.08 mg/kg) or the MRL of Japan (0.5 mg/kg).