The endangered semi-mangrove plant Heritiera littoralis occupies an overall area of less than 30 hm² in China. In this study, we employed the MaxEnt model to predict the distribution patterns of H. littoralis during the Last Glaciation Maximum, the present day, and the future. Drawing from 41 distributed records and 12 environmental factors within China, we investigated the species’ potential habitats. To anticipate future scenarios, we assessed its distribution under the RCP4.5 greenhouse gas emission scenario for 2050 and 2070. As a result, four primary distribution areas emerged in Guangxi, Guangdong, Hainan, and Taiwan, signifying the main potential habitats for H. littoralis. Our findings indicate that the distribution centre of H. littoralis remains in Guangxi across the four time periods, with a projected eastward migration. By 2050, the species’ habitat range is anticipated to contract, whereas, by 2070, the suitable habitat area is expected to expand. Moreover, we identify pivotal environmental factors influencing the potential distribution of H. littoralis, including precipitation of the warmest quarter (Bio 18), temperature seasonality (Bio 4), mean diurnal range (Bio 2), precipitation of the wettest month (Bio 13), and annual mean temperature (Bio 1). The outcomes of this study offer valuable data for comprehending the distribution of H. littoralis in China. Furthermore, they aid in pinpointing areas suitable for conservation management, both presently and in the future.