Abstract: Human computer interactive target tracking is improved by combining adaptive background extraction in static backg-round with extend mean shift algorithm.Firstly build a background image in the complex background with a moving object and obtain initial object contour from the current image by frame-difference.When tracking by mean shift algorithm，the covariance matrix is added to mean shift，and it can solve the problem of the tracked object departure.The experiments indicate that the algorithm can track the object accurately and effectively.