Abstract: Mangroves, which grow in coastal habitats affected by tides, have important ecological functions and biological values. Understanding the water relationships of mangrove plants is an important area of research. Due to the influence of salty habitats, the water potential of mangroves is generally low. The water transportation system of mangroves exhibits high embolism resistance. Furthermore, mangrove water use is conservative, with water consumption in the low range for terrestrial tropical trees. Mangrove species show high phenotypic plasticity, high drought and salt tolerance, and diverse water management strategies in order to adapt to their intertidal environments. Their water transport efficiency is not low, which can support high photosynthesis when environmental conditions are favorable. The present paper reviews the characteristics of mangrove water use, as well as water and salt management strategies. We also propose future research areas on the water relationships of mangrove plants from multiple perspectives combined with new research techniques.