Abstract：Liquid chromatography with UV detection was used to determine pyraclostrobin residues in Chinese cabbage〔Brassica compestris L. ssp. pekinensis（Lour）Olsson〕．The dynamics of degradation of pyraclostrobin residues in Chinese cabbages in Hebei and Hunan Provinces were studied．The results showed that the limit of determination was 0.04 mg?kg-1．The recoveries were 70%～106% and coefficients of variation were 6.6%～10% between the concentration of 0.04～2.00 mg?kg-1．The results indicated that the half lives of pyraclostrobin in Chinese cabbages in Hebei and Hunan were 2.97 d and 3.34 d，respectively．According to the research findings，when pyraclostrobin being applied 3 and 4 times to Chinese cabbage fields with dosages of active ingredient of 187.50 and 281.25 g?hm-2，the residues of pyraclostrobin in Chinese cabbages 7 days after the last application were between 0.96～2.70 mg?kg-1．
