A method for positioning a mobile device includes following steps. Based on a prior location point of the mobile device, many sample points are generated according to a prior probability distribution associated with the prior location point. A current moving track or a current moving status of the mobile device is obtained, and the sample points are updated according to at least one of the current moving track and the current moving status. A current estimated position is obtained based on a radio frequency signal received by the mobile device. A current probability distribution of the sample points corresponding to the radio frequency signal or the current estimated position is generated to obtain corresponding weights of the updated sample points. A current location point of the mobile device is obtained according to the weights and distribution of the sample points.