In order to investigate the effects of different dietary protein species intake on plasma homocysteine concentration in rats.Methods 48 Wistar rats were fed with casein, lactalbumin, egg albumin, SPI, wheat gluten and zein diets for 10 days, and sacrificed to collect blood sample for analyzing the concentration of plasma homocysteine, cysteine, GSH and Cys-Gly.Results Body weight gain of wheat gluten group was significantly lower than casein, lactalbumin, egg albuminand and SPI, while negative growth was observed in zein group(P＜0.05). The plasma homocystein concentration of wheat gluten and zein group was significantly lower than other groups, and the plasma homocystein concentration in lactalbumin group was significantly lower than casein group.Conclusion The effects of different dietary protein species intake on plasma homocysteine concentration mainly depends on protein species and the contents of amino acid. The main mechanism is that the increased cysteine concentration promote enzyme activities of homocystein metabolism, and increase the consumption of homocysteine.