As part of the plant water-use process, plant nocturnal sap flow (Qn) has been demonstrated to have important ecophysiological significance to compensate for water loss. The purpose of this study was to explore nocturnal water-use strategies to fill the knowledge gap in mangroves, by measuring three species co-occurring in a subtropical estuary. Sap flow was monitored over an entire year using thermal diffusive probes. Stem diameter and leaf-level gas exchange were measured in summer. The data were used to explore the different nocturnal water balance maintaining mechanisms among species. TheQnexisted persistently and contributed markedly over 5.5%~24.0% of the daily sap flow (Q) across species, which was associated with two processes, nocturnal transpiration (En) and nocturnal stem water refilling (Rn). We found that the stem recharge of theKandelia obovataandAegiceras corniculatumoccurred mainly after sunset and that the high salinity environment drove higherQnwhile stem recharge of theAvicennia marinamainly occurred in the daytime and the high salinity environment inhibited theQn. The diversity of stem recharge patterns and response to sap flow to high salinity conditions were the main reasons for the differences inQn/Qamong species. ForKandelia obovataandAegiceras corniculatum,Rnwas the main contributor toQn, which was driven by the demands of stem water refilling after diurnal water depletion and high salt environment. Both of the species have a strict control over the stomata to reduce water loss at night. In contrast,Avicennia marinamaintained a lowQn, driven by vapor pressure deficit, and theQnmainly used forEn, which adapts to high salinity conditions by limiting water dissipation at night. We conclude that the diverse waysQnproperties act as water-compensating strategies among the co-occurring mangrove species might help the trees to overcoming water scarcity.