Two kinds of algorithms are proposed to dynamically estimate the precise of the Virtual Channel Model(VCM) to improve the performance of Distribution Video Coding(DVC) system.According to the temporal dynamic property of the VCM,a new frame level VCM estimation algorithm at the decoders is proposed.For each coding frame,the bidirectional vectors acquired in side information interpolation are used to get motion compensated versions of the key frames,then,the residuals of the key frames and their compensated motion versions are used to estimate the VCM of current coding frame.According to the spatial dynamic property of the VCM,a novel block level VCM estimation algorithm is proposed also.The video frames are divided into blocks,then the VCM estimation algorithm proposed is adopted to get its own VCM for each block.Experimental results show that for different video sequences,the proposed algorithms improve rate distortion performance by 0.5~1 dB for the DVC system,and reduce transmission code rates for video encoding systems.