PROBLEM TO BE SOLVED: To provide a natural extract having antithrombotic effect, and a medicine, quasi drug or food containing the same, which can prevent and improve thrombosis or reduction in blood circulation due to a thrombus.SOLUTION: Extracts of marigold, passion vine, eyebright and balsam apple have excellent antithrombotic effects. A Ganoderma extract is used in combination therewith, whereby a synergistic effect is obtained. The food, quasi drug or medicine containing such an extract has antithrombotic effect, and is effective not only for improvement of thrombosis but also for prevention and improvement of symptomatic states involving thrombus such as arteriosclerosis, dullness of skin, dementia, shoulder stiffness, and headache.