In the field of computer vision, many kinds of camera parameter estimation methods have been proposed. As one of these methods, an extrinsic camera parameter estimation method that uses pre-constructed feature landmark database has been studied. In this method, extrinsic camera parameters of video images are estimated from correspondences between landmarks and image features. Although this method can work in a large outdoor environment, its computational cost in matching process is expensive and it cannot work in real-time. In this paper, to achieve real-time camera parameter estimation, the number of matching candidates are reduced by using priorities of landmarks that are determined from previously captured video sequences.