As the footstone for national security and social stability, the significant condition for economic and social development and the basic guarantee for people's peaceful living and work, the public security is a "people-oriented"commonweal cause that protects public lives and properties. With the maturity of human material civilization, the state, society and people have an unprecedented dependence on and desire for security. The public security has become one of the most important warranties for the benign economic and social growth and the normal national management of global countries. Containing such grave problems as national important infrastructures and security safeguard in key sites, the problem of public security safeguard involves four fields, i. E. Natural disaster, accident calamity, public health and social security as well as various public emergencies that endanger public lives and properties, e. G. Flood, tsunami, fire, explosion, leakage of poisonous matters, leakage of radioactive source, SARS, Bird Flu, , major criminal case, terrorist raid. It also implicates the problems in aspects of inspection & monitoring, prediction and pre-warning, integrated emergency management, private defense and so on.