A device for performing authentication and authorization checking on Location-Based Service (LBS) in a WiMAX network is provided. This device strengthens security for LBS in a WiMAX network, and protects privacy right of subscribers to LBS. The device includes a Location Assessment module (LA) for performing the location assessment, a Location Coordination and control module (LC) for controlling LBS assessment and calculation of a location of a mobile terminal. The device also includes an Authentication/Authorization/Accounting module (AAA) that includes a memory storing authentication and authorization information. The AAA also includes an authentication processing module for authenticating an LBS, and an authorization checking processing module for checking whether an LBS client and a Mobile Station (MS) requesting services from the LBS are authorized to request the location of a target MS.