In this paper, we make an introduction to the security management in the next generation wireless mobile net- works, including the access security mechanisms in the circuited-switched domain, packet-switched domain and emerging IP multimedia subsystem domain. Several re- search challenges are identified, including security architecture with network heterogeneity, energy-security trade- offs and mobility-security interaction. The identified is- sues can serve as the potential guidance for further study to satisfy higher security requirement and lower introduced overhead.