The traditional Mean-Shift tracking algorithm is not applied to track a size-changing target effectively due to the fixed band-width of its kernel function.For this reason,a new algorithm is proposed.In each frame,Mean Shift tracking algorithm is employed to get the target location,and then the affine structure between frames is calculated to re-correct the position and size of the target.Different experiments prove that the present method has better stability and robustness than the traditional algorithm.