The dynamic changes of liver microsomal drug-metabolizing system ( MDMS) and lipoperoxidation were studied in scalded rats.The effects of treatment with vitamin E and silybin were also evaluated.The results showed that liver microsomal cytochrome P-450 content, and p-nitroanisole demethylase (p-NOD) and aniline hydroxylase (AH) activity decreased markedly postburn.On the contrary, liver lipoperoxide and microsomal lipoperoxidation increased significantly after scalding.Both the increase of liver lipoperoxide and microsomal lipoperoxidation and the decrease of MDMS activity were prevented by vitamin E and silybin treatments.