Abstract: Four groups of rats were fed semi－ purified cholesterol－ enriched diet containing 4 different sources of proteins (soybean protein,casein,wheat protein,wheat and soybean protein mixture) for 45 days so as to study the effects of dietary animal and plant proteins on serum cholesterol metabolism.As compared with casein,soybean protein and its mixture with wheat protein induced significantly lower concentration of serum total cholesterol (TC) and LDL－ C,lower (VLDL－ C＋ LDL－ C)/TC ratio and higher level of HDL－ C and HDL－ C/TC ratio (P<0.05).LDL－ C also was significantly lower in the rats fed wheat protein than the rats fed casein,whereas HDL－ C was significantly higher in rats fed wheat protein than casein (P<0.05).The mixture of wheat protein and soybean protein showed stronger cholesterol－ lowering effect,and also improved biological value of wheat protein.The results suggested that soybean protein,especially the mixture of wheat protein and soybean protein had preventive effect on atherosclerosis.

Key words: Diet Protein Serum cholesterol Rats