The invention discloses a topic grouping method and system based on geographic position information. The method comprises the following steps: S1, a user sends out a positioning request through a client; S2, the client acquires the geographic position information of the position of the user; S3, the client automatically sends the geographic position information of the user to a positioning server; S4, the positioning server receives the geographic position information of the user; S5, the positioning server searches the topic group corresponding to the geographic position information of the user; and S6, the positioning server returns the geographic position information of the user and the corresponding topic group to the client. The invention connects the position service of mobile communication equipment and a social network, enhances the interaction of users, improves the social experience of the user, translates the longitude and latitude of the position of the user into a concrete geographic name to be stored in a database, reads the data from the database and outputs to a page, and ensures real-time update of the data, thus the positioning is accurate and can be accurate to a range of 50m.