Abstract: Shock, which has been clinically recognized and treated for many years, is a common life-threatening disorder. In recent years, with the development of hemodynamic theory, the assessment and understanding of shock have been progressing. Based on the latest knowledge, Chinese experts of critical care medicine attempted to define a Chinese definition of shock: an acute circulatory syndrome with insufficient perfusion to tissues and organs, which is due to changes in perfusion flow by various causes. According to the characteristics of hemodynamics and clinical application, shock is still classified into four groups: distributive, hypovolemic, obstructive, and cardiogenic. If different types of shock coexist, it is called "mixed shock". Therefore, it helps us to better understand, evaluate and manage this situation, so that more patients with shock can benefit from it.