A good target tracking system depends on not only the algorithm, but also system hardware design. Speed and accuracy are two important evaluations indicators in target tracking system. This paper uses Harris algorithm to extract little part of target corner features which can improve this system's speed. Then, it uses optic flow method which has high matching accuracy to match those extracted corner features in the following video frames. Bary algorithm is used to compute the bary of those matched feature points as displacement of target.