The effects of black soybena extracts on enzymes activies of rat were evaluated in present study. Eighty-four male Sprague-Dawley rats weighing 100$pm$10g were divided into twelve groups which consisted of black soybean extract, Pb and Cd solution, and black soybean extract plus Pb or Cd soln groups. The weight gain was increased in black soybean extracts and Pb soln solution group but decreased in Cd soln solution group. The results obtained form the experiment were as follows: Glutamate pyruvate trasaminase (GPT) and glutamate oxaloacetate oxaloacetate transaminase (GOT) activities were not significantly different among experimental groups. The lactate dehydrogenase (LDH) activities of black soybean extract administered groups were decreased than those of Pb and Cd solution group. Black soybean group increased cholinesterase (ChEase) activity as compared to administration of Pb and Cd soln group.