American military medical security system,with leading concept and level globally,has been tested and reformed in many wars.Especially,in Oct.2013,the American Military Health System (MHS) launched the largest organizational structure adjustment in its history,and the Defense Health Agency was established.Its medical support system is increasingly scientific and its structure is increasingly reasonable.It has established a support system based on the MHS and supplemented by the civil health system.It not only distinguishes between peacetime and wartime medical support,but also emphasize the transformation of peacetime and wartime support systems,with the characteristics of separating construction and management,flexible mode,integration of military and civilian,efficient operation,etc.It plays a positive role in maintaining and improving the combat readiness capability of the American military medical services,improving medical service,and promoting medical treatment capability.At present,the construction of the medical support system of our army has entered a critical period of transformation and development.We can learn some concepts and experience from American medical security system in terms of the determining health service status,transformation of health service systems,and health service support mode,so as to establish a more scientific and efficient health service support system.