Abstract: It is difficult to geometrically rectify remote sensing images in personal computer because of the large data. A PC-based fast algorithm of geometric rectification is presented to solve this problem. Three techniques are adopted in the algorithm: (1) fast calculating the polynormal by separating column items from rows; (2) accessing optimal rectangle sub-image according to the allocated computer memory; (3) processing all bands simultaneously. These techniques make the algorithm fast and suitable for images with any size. The implementation and performance of the algorithm are also discribed in this paper.