Human behavior analysis and visual anomaly detection are important applications in elds such as video surveillance, security systems, intelligent houses, and elderly care. People re-identi cation is one of the main steps in a surveillance system that directly a ects system performance; and variations in appearance, pose, and scene illumination may be challenging issues for such a system. Previous re-identi cation approaches faced limitations while considering appearance changes in their tracking task. This paper proposes a new approach for people's re-identi cation using a descriptor that is robust to appearance changes. In our proposed method, the enhanced Gaussian Of Gaussian (GOG) and the Hierarchical Gaussian Descriptors (HGDs) are employed to extract feature vectors from images. Experimental results on a number of commonly used people re-identi cation databases imply the superiority of the proposed approach in people re-identi cation compared to other existing approaches.