Aiming at the problem that the conventional spatio-temporal context（ STC） target tracking algorithm can lead to tracking failure when total occlusion or overshooting area is too large

a target tracking algorithm which combines STC with Cam Shift is proposed. By setting a threshold

determine when the STC algorithm detects the target occlusion.When entering the occlusion

the tracking center obtained by the Cam Shift algorithm is used to correct the tracking center calculated by the STC model and update local context area with the revised center.Experimental results show that the proposed algorithm is more robust and stable than the original one in adapting to more complicated scene changes.