Abstract: GC-MS/MS was applied to the determination of 10 organic tin compounds in toy products. The sample was extracted with simulated gastric acid, and the extract was derivatized with sodium tetraethyl borate and determined by GC-MS/MS under the mode of multi reaction monitoring (MRM). As shown by the results, linear relationships between values of peak area and mass concentration of the 10 organic tin compounds were obtained in the same range within 1.0 mg·L-1, with detection limits (3S/N) in the range of 0.065-2.6 μg·kg-1. Recovery and precision of method were tested by standard addition method, giving values of recovery in the range of 85.1%-103%, and RSDs (n=6) in the range of 3.9%-10%. This method was proved to be satisfactory for the determination of organic tin compounds in toy products.