Abstract: To study geometric quality influence of remote sensing image brought by image compressing system, a new image geometric quality assessing algorithm based on image corner point is proposed. First, classic Harris corner detecting algorithm is introduced, then it is improved to solve its disadvantage of imprecise point location: fitting the surface of corner response function and evaluating peak location of the fitted surface, so as to check the sub-pixel corner location. Finally, this algorithm is applied to geometric quality assessment system of remote sensing image, and is compared to traditional surface fitting extremum algorithm. The experimental results show that this algorithm can accurately express the aberration of geometric quality between orignal image and compressed one. So, it can be used into quality assessment system of aerial remote sensing image compression.