Catalase (CAT) is a hydrogen peroxide (H2O2) scavenging enzyme and plays a central role in plant growth, development and stress response. Its function is strictly regulated to keep an appropriate concentra-tion of H2O2 as a signal molecule under normal conditions to ensure plant growth and development, and to maintain H2O2 homeostasis under stress conditions to enhance plant stress tolerance. This review summarized the recent research progress of CAT in plant growth, development and stress response, especially the regula-tion of CAT function by post-translational modification and subcellular localization. It also made suggestions for future research on the regulatory mechanism of CAT in plants.