Abstract: Urban forest is an important component of urban ecosystem, which has significance in reducing atmospheric CO₂ concentration, mitigating the negative effects of climate change, and improving regional environmental situation, being a hot topic in related studies. This paper summarized the studies on the urban forest carbon (C) sink, and evaluated the characteristics of urban forest C sink from the aspects of the spatiotemporal distribution of C sink and the relationships between urban forest and low C development. The principles and applications of three main estimation methods widely used for estimating urban forest C sequestration, i.e., sampling site inventory, remote sensing estimation, and microclimatology, were summarized. The shortcomings and development directions of the current researches of urban forest C sequestration were discussed, and the advantages, disadvantages, and applicability of different estimation methods of urban forest C sink were analyzed. It was suggested that the comprehensive application of sampling site inventory, model simulation, and remote sensing analysis would be the main trend for resolving the issues of multiscale coupling, improving the estimation accuracy, and studying the C cycle of urban forest ecosystems.