Cholesterol-degrading strains was isolated from traditional koumiss. The effects of Lb. casei Zhang on the total serum cholesterol (TC) , triglycerid (TG), high density liporotein-cholesterol (HDL-C) low density liporotein-cholesterol (LDL-C) were investigated in artificially-induced hyperlipemial rats. The results showed that only heat-killed cells of Lb. casei Zhang significantly reduced serum TC (P