Abstract: Nattokinase is a serine protease produced by Bacillus natto in the process of fermenting natto. It has physiological functions such as dissolving blood clots. This article briefly summarizes the thrombolytic function and mechanism of nattokinase, focusing on the research progress of nattokinase activity determination methods and other quality indicators and safety evaluation. The research direction of nattokinase product development and quality and safety is prospected, in order to provide a theoretical basis for the standardization of natto and its products (including nattokinase products).