This paper presents a fusion-based target tracker (FBTT) for tracking a target detected by sector scan radar. The tracker employs two Kalman filters (KF) in dual-path structure. Estimation of target state in minimum mean square sense (MMSS) is obtained through fusing estimations exported from two Kalman filters, respectively. With the framework proposed here, most prevalent maneuvering target tracking algorithms in annular scan radar system can be readily applied for sector scan radar without the overburden of computation. Performance comparison between FBTT and Kalman filter is demonstrated through simulations. Benefit and validity of the proposed method is verified