An athrombogenic material, exhibiting selective proteolytic activity, was developed. The material was obtained after modification of polyethylene by means of the polymer complex containing polyacrylic acid and E-caprolactam. The modified polyethylene was treated with thionyl chloride and then it was maintained in the solution containing streptokinase or urokinase. The athrombogenic material exhibited fibrinolytic activity within 15 days; its athrombogenic properties were studied in vitro.