Location-based Services (LBS) are a kind of important applications which identify the resources close to users, i.e. return the nearest gas stations, restaurants, banks etc, as well as identification of the optimal route to reach destination according to user position. However, privacy threat is the inherent problem in LBS as the location data is very effective for service provisioning. Thus, we focus on the privacy issue. We apply the deniable authentication to LBS. Intuitively, user is not afraid of his location data exposure to service provider (SP) for service request since SP has no evidence to show user's request to any third party under the deniable authentication. In this way, it is not necessary for user to provide coarse location information which would degrade the service quality certainly.