Abstract: The goal of person re-identification (ReID) is to retrieve a specific person between multiple non-overlapping cameras. Representative deep-learning-based person ReID methods were reviewed and the architectures and features of different person re-identification methods were discussed in this paper. First, the definition of person ReID was introduced. Second, supervised learning methods and weakly supervised learning methods were reviewed, respectively. In particular, The feature representation learning and metric learning of the supervised learning methods were discussed in detail. Third, the mainstream datasets in different tasks were analyzed, and the state-of-the-art methods were evaluated and compared. Finally, important yet under-developed research directions were briefed.