Abstract: The pyrolysis products of vitamin E at 300℃,600℃ and 900℃ in atmosphere of air,nitrogen of 9% oxygen and helium respectively was analyzed by pyrolysis- cryo-trap(CIS)-gas chromatography-mass spectrometry ( PY-CIS -GC/MS).The results showed that: ①Vitamin E at all pyrolysis atmospheres and temperatures have the following pyrolysis products:nonanal,cyclopropane, 1-methyl-2-pentyl-,vitamin E;②Pyrolysis products of vitamin E at 900℃ and 600℃,for the same pyrolysis temperature,with decreasing of pyrolysis oxygen content,the quantity and content of alkenes decrease,and the quantity decrease and the content increase of alkanes,while the quantity and content of ketones,aldehydes,alcohols,esters,furans decrease;with decreasing of pyrolysis temperature,for the same pyrolysis atmosphere,the quantity and content of alkenes,alkanes decreas while the quantity and content of ketones,aldehydes,alcohols,esters,furans change little;③At 300℃,the main pyrolysis products is vitamin E,nonanal and alkanes are also included;④Vitamin E transferred to its own pyrolysis products directly shows little difference in content at 600℃and 900℃,the average content is 17.80%;in air,nitrogen of 9% oxygen and helium this content at 300℃ are:90.24%,84.61% and 75.60%respectively.