1. A method of peer-to-peer instant messaging for a mobile terminal, said mobile terminal comprising a pre-stored contact list which includes at least one list of particular users, said method comprising: receiving, at a mobile terminal, a list of on-line users that have capability of peer-to-peer instant messaging which is sent by a radio network; comparing, at the mobile terminal, said list of particular users with said received list of on-line users; and updating, according to said comparison result, connection status record of each user in said list of particular users, to make the mobile terminal to establish peer-to-peer instant messaging with at least one user mobile terminal in said list of particular users according to said updated connection status record, wherein the list of particular users is a subset of the contact list.