We propose a method for estimating the credibility of the posted information from users. The system displays these information on the map. Since posted information can include subjective information from various perspectives, we can't trust all of the postings as they are. We propose and integrate factors of the user's geographic posting tendency and votes by other users. Categories and Subject Descriptors H.4.2 [Information Systems Applications]: Decision support General Terms Algorithms, Experimentation, Human Factors Keywords credibility, posting, GIS, navigation, recommendation