Abstract: In this paper, Laplacian of Gaussian (LoG) of contour curves is applied and its norm square shows a robust curvature feature. So, norm square of contour LoG is defined as the response function of corners. Further, a novel covariant region detector with rotation and scale invariants is designed based on the contour orientation of each point at neighbor of each corner detected by LoG and the corner itself. Finally, matching among image feature covariant regions is performed using cross correlation criterion and the results illustrate that the proposed algorithm has the properties such as simple calculation, easy realization, and better robustness.