Abstract: An analytical method for the determination of thidiazuron in kiwi, cucumber, apple and grape was established using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The samples were extracted with acetonitrile, purified by primary secondary amine (PSA) and detected with HPLC-MS/MS. The results indicated that in the concentration of 0.01-1 mg/L, the matrix-matched calibration curves showed good linearity and determination coefficients >0.99. In the concentration of 0.01-0.5 mg/kg, the average recoveries of thidiazuron in the four matrices were found between 87% and 102% with 0.8%-2.0% relative standard deviations (RSD).The limits of quantification (LOQ) were 0.01 mg/kg. The method was convenient, efficient, economical, sensitive and accurate, which can be suitable for determination of thidiazuron residues.