Abstract: This paper reported residual dynamics of abamectin 3% ME in pear and soil. Dissipation dynamics and final residues of abamectin in pear and soil were determined by HPLC with pre-column fluorescent derivatization. The results showed that the sensitivity, accuracy and precision of the method accorded with the requirement of pesticide residue analysis. The half-lives of abamectin were from 1.1 days to 2.6 days in pear, and in soil were from 2.1 days to 5.7 days. The maximum final residue of abamectin in pear was 0.0090 mg/kg, while in soil was 0.0157 mg/kg. For the moment, the MRLs of abamectin in pear were regulated as 0.02 mg/kg in China. On that, abamectin 3% ME was applied to control Psylla chinensis Yang et Li with the dosage less than 18 mg a.i./kg and used from 3 to 4 times, the safety interval was 7 days.