This study was undertaken to determine the effect of yellow and black soybeans on plasma and hepatic lipid composition and fecal lipid excretion in Sprague Dawley rats. Animals were fed with diets containing 52% yellow soybean, 50% black soybean, or 20% casein for 7 weeks. Feeding efficiency was significantly increased in the animals fed soybeans(p<0.05). Plasma cholesterol concentration was significantly lowered in the group fed yellow soybean compared with black soybean and casein-fed control (p<0.05). Hepatic triglyceride concentration was significantly lowered in soybean groups compared with casein-fed control(p<0.05), whereas hepatic cholesterol concentration was not affected by diet treatments. Soybean feeding significantly increased fecal weight, triglyceride and bile acid contents compared with casein feeding(p<0.05). It is concluded that soybean feeding in rats affects plasma and hepatic lipid levels by increasing the excretion of triglyceride and bile acids.