A correlative reacting system and a method for implementing security update of mobile station. The correlative reacting system includes a security correlative agent at a terminal side and a security correlative server at a network side communicated with the security correlative agent via an air interface. In the present invention, the correlative reacting system performs an information interaction with the mobile station, controls the mobile station to carry out an automatic security update. The automatic security update includes automatic downloading and installation, update of the security correlative agent, and automatic recovery of the insecurity factors of the mobile station and the like.