Abstract: An approach of multisensor target tracking and data fusion is introduced. After Kalman filtering for every sensor data, the track of target for every sensor is obtained. Then a data fusion method for all these target tracks is presented. This approach improves the precision of target location and has following advantages. First it directly deals with the tracking of target under Cartesian coordinates after Kalman filter, so it avoids the complicated location conversion among the different sensors. Moreover, the errors of the target tracking are obtained after Kalman filter, so this approach avoids the complicated errors conversion too. In a word, this approach is succinct and efficient.