Abstract: Spirotetramat is commonly used in citrus orchards for pest control. A study was performed on residues of the pesticide and its metabolites in citrus and soil, their degradation dynamics and their fates in citrus orchards located at Suzhou, Fuzhou and Chongqing, using acetonitrile in extraction, N-propyl ethylenediamine (PSA) and anhydrous magnesium sulfate in purification, and the LC-MS/MS in determination. Results show that half-life of spirotetramat was in the range of 6.7-9.6, 4.7-9.5 and 7.8-9.5 d in the fruits from Suzhou, Fuzhou, and Chongqing, respectively, and in the range of 1.4-2.3,1.3-4.9 and 2.3-3.6 d in the soils from the orchards at Suzhou, Fuzhou, and Chongqing, respectively. On such a basis, it is suggested that spirotetramat be applied at a rate of the highest recommended dosage (60 mg·kg^-1 in active ingredient) and a rate, 1.5 times the highest recommended dosage (90 mg·kg^-1, in active ingredient) twice and three times a season to keep residue of the substance in citrus below the upper limit of MRL (1.0 mg·kg^-1).