Abstract: Mass spectrometry in hyphenation with gas chromatography was applied to the determination of 3,5-bi-neo-butyl-4-hydroxy-toluene (BHT) in polyethers with headspace enrichment.As compared with the solvent extraction method of enrichment of BHT,the proposed method showed its advantages of avoiding the use of relatively large amount of solvent making the operation much simpler and the analysis much faster,while the results obtained were in consistency with those obtained by the solvent extraction method.