In order to investigate the effect of ginseng saponins on the activity of lipoprotein lipase, it was attempted to conform the enzymatic hydrolysis of chylomicron with post-heparin induced plasma lipoprotein lipase of normal rabbit in vitro. And the activity of lipoprotein llipase was determined by the quantitative determination of liberated free fatty acids on the hydrolysis of chylomicron. As the result, it was observed that the ginseng ssaponins accelerated the hydrolysis of chylomicron by post-heparin plasma in vitro. And the optimum concentration of ginseng saponins for the activity of the lipoprotein lipase in the 」% bovine serum albumin was 10^-4%. But ginseng saponins on the hydrolysis of chylomicron was influenced by the presence and the absence of albumin. And the optimum concentration of albumin and Na-cholate on the activity of lipoprotein lipase was each of the 10^-6% albumin and 5mM Na-cholate. From these results, it seems that ginseng saponins might stimulate the intravascular hydrolysis of chylomicron.