Different plastic samples were dissolved completely in tetrahydrofuran（THF）,the impurities of high molecular weight were precipitated with methanol and separated by high speed centrifugation and filtration.The target organotin compounds were derivatized with sodium tetraethylborate in acetic acid and sodium acetate buffer solution.The ethyl derivatives of organotin compounds were extracted with n-hexane and then qualitatively and quantitatively analyzed by gas chromatography.The derivatization conditions such as derivatization time,pH value,derivatization reagent were optimized.10 organotin compounds（dimethyltin,trimethyltin,diethyltin,n butyltin,dibutyltin,tetrabutyltin,di n-octyltin,tricyclohexyltin,diphenyltin and triphenyltin） in plastic samples of PVC,PC,PS,AS and ABS were determined by gas chromatography coupled with dual column and dual detectors of mass spectrometry and flame photometric detector.10 mixed organotin compounds ranging from 0.01 to 10 mg/L were tested by the external standard method.The experimental results indicated that the correlation coefficients of calibration curves（r） for the organotin compounds were over 0.999.The average spiked recoveries were in the range of 75.1%-110.1% with relative standard deviations less than 10% in ABS,PS and PVC plastic samples，and the detection limits for 10 organotin compounds were in the range of 0.005-0.037 mg/kg.The method showed good extraction efficiency,high sensitivity and good reproducibility,and was suitable for the determination of organotin compounds in different plastic products.