A rectification approach for catadioptric omnidirectional image pair via the rectification of corresponding unwarping cylindrical image is proposed.The acquisition and unwarping process of omnidirectional image is discussed firstly.Then，according to imaging principle of cylindrical panoramic image，corresponding epipolar geometry and solving is analyzed.Meanwhile this paper develops an criteria for resampling-effect assessment depending on the degree of pixel information exploitation that rectified images based on the reference images.And it shows that，under this criterion，rectification for cylindrical image by resampling reference images along epilines has obvious advantage in terms of pixel-maintain-rate and effective-pixel-rate compared to other approaches.To reduce resolution degradation and image deformation resulted from proposed rectification algorithm，issue of how to sampling reference images maximum as much as possible according to the epipolar geometry is mainly studied and solved.Lastly results of our approach applied to both synthetic and real scenes are given at the end of this paper.