Abstract: An analytical method using the on-line gel permeation chromatography- gas chromatography/mass spectrometry has been developed for the determination of 6 organotin compounds in tea．After acidified by hydrochloric acid, the sample was extracted with acetone-hexane,the crude extract was concentrated, dehydrated, and derivatized by n-pentyl magnesium bromide. Then the derivative was extracted by n-hexane and purified on a Envi-Carb and Florisil solid phase extraction column, and then analysed on an on-line gel permeation chromatographic-gas chromatographic/mass spectrometer(GPC-GC/MS)．The recoveries in the spiked sample with standards of 0.01, 0.05 and 0.10 mg/kg were 66.2%～105.6％，and the relative standard deviations were between 2.7%～10.4％．The limits of detection were 0.01 mg/kg．The method is proved to be rapid, easy, accurate, highly sensitive, and can be used for the simultaneous determination of organotin compounds in tea．