A method for protecting a service account includes: configuring association information for a service account of a user in a Personal Communication Profile (PCP) of the user at a network side; authenticating the association information when the user logs on an application server with the service account through User Equipment (UE); allowing the user to log on the application server if the authentication succeeds. Embodiments of the present invention also disclose systems, PCP storage apparatuses and application servers for protecting the service account. In embodiments of the present invention, besides protecting the service account by a static password, the user can implement an enhanced protection for the service account without receiving the dynamic password through a short message, which dramatically reduces the time delay for the user to log-on the application server. Further, the user needs not purchase the password card additionally. Therefore, the competitiveness of the application server is improved.