The present invention relates to a field of communication technology that provides a method, system and device of location authentication. The method comprises the following steps: the mobile device receives the signal marking the position information of the location base station sent by the location base station within the same region. The mobile device would obtain the position information of the location base station after analyzing the signal; the location base station would send the position information to the location authentication server to obtain the location authentication that it is in the same region with the location base station. Thus, this invention performs the location authentication of the mobile device staying in the same region with the location base station.