Abstract: To look for a capillary gas chromatographic method of seperating toluene diisocyanate, the columns' ability to separate toluene diisocyanate isomers was studied. The columns were coated with typical gas chromatographic stationary phases, such as SE-30, SE-54, OV-225, PBHpB, HDI and the influence of the flow velocity and temperature on the resolution of 2,4/2, 6-TDI was considered. The best gas chromatographic stationary phase to analyze 2, 4/2, 6-TDl was selected. Experiments showed that the best gas chromatographic stationary phases to separate toluene diisocyanate lsomers is OV-225. It is a simple, quick and accurate method to analyze and detect toluene diisocyanate isomers.