In this paper,a change intensity indicator of land cover based on cross correlogram spectral matching(CCSM) technique was employed to generate the change intensity image of the cropping vegetation cover area in North China between two TM images in different periods.It was first considered that the change intensity of image pixel of the two-order neighbor in the change intensity image obeyed the hidden markov random field model,and then the vegetation cover change area was extracted from the change intensity image using maximum a posteriori estimation of markov random field(MRF-MAP) model.The experiment has proved that the proposed method could precisely extract vegetation cover change and inhibit effectively the same object with different spectra due to exogenous noises in the cropping vegetation cover area.However,this method seems to perform unsatisfactorily over the water area.