The purpose of the presented study is a comparison of phytooestrogen--coumestrol and oestrone effects on carbohydrate metabolism in ovariectomized female rats and to examine the participation of pancreatic hormones in changes of this metabolism. Administration of coumestrol diminished muscle glycogen in investigated animals. There were no significant changes in insulin and glucagon blood level but decrease in the specific insulin binding in the muscle membranes was observed. It suggests that coumestrol effects the insulin receptor activity in this tissue and it could be a cause of glycogen deficiency.