The invention discloses a method for an instant messaging system to search good friends, wherein, personal information input by an instant messaging user is stored into a user information database. The method comprises that: according to the personal information of a first instant messaging user stored in the user information database, an instant messaging user which the first instant messaging user wants to search is searched, and the found personal information of the instant messaging user is displayed. The invention also discloses a method for the instant messaging system to add good friends, a system for the instant messaging system to search good friends and a system for the instant messaging system to add good friends. The invention can ensure that IM users conveniently and quickly find out the good friend to be searched.