A small molecule peptide Leu-Asp-Tyr-Glu(LDYE) prepared from the enzymatic hydrolysate of zein was tested for its anti-oxidative activities. The effects of LDYE on the turgidity of mitochondria,the fluidity of membrane,the activity of cytochrome C oxidase and ATPase at subcellular level were investigated by using H\-2O\-2/Fe\+\{2+\} -induced mitochondria damage model system. It was found that the small peptide exhibited an obvious ability of removing free radicals and protecting the mitochondria from damage by oxidation. [WT5HZ]