Ammopiptanthus plants, including Ammopiptanthus mgolicus and Ammopiptanthus nanus, are tertiary endangered species of paleo-Mediterranean origin that are primarily distributed in arid and semi-arid regions in northwestern China. A. mgolicus and A. nanus not only play an important role in the ecological environment of northwestern China but are also important species for scientific research. Global climate change and anthropogenic activities have caused the distribution of Ammopiptanthus plants to shrink, and currently they are on the verge of extinction. In this study, ecological niche models (MaxEnt model, Bioclim model, and Domain model) were used to predict the past (Last Interglacial and Last Glacial Maximum), current, and future (RCP4.5 and RCP8.5 scenarios in 2050) potential distributions of Ammopiptanthus plants in China. The accuracy of the MaxEnt model for modeling the potential distribution of Ammopiptanthus plants was high, and average values of the area under the receiver operator characteristic curve (AUC test value) were higher than 0.80 for all models. The best suitable and high suitable areas for the current potential distribution of A. mgolicus accounted for 2.78% of the total area of China and primarily occupied central Inner Mongolia, Ningxia, and Gansu. The best suitable and high suitable areas of the future potential distribution of A. mgolicus revealed expansion into central Inner Mongolia, northern Gansu, and northern Ningxia by 2050, with much of the distribution concentrated in Etuoke Banner, Ordos, and Alxa Zuoqi of Inner Mongolia; Wuzhong City of Ningxia; and Minle City of Gansu. The best suitable and high suitable areas of the current potential distribution of A nanus accounted for 2.23% of the total area of China and primarily occupied southern Xinjiang. The best suitable and high suitable areas of the future potential distribution of A. nanus revealed expansion into southern Wuqia County and north of Urumqi in Xinjiang by 2050, with much of the distribution concentrated in Wuqia County, Wusu City, Turpan City, and Urumqi City in Xinjiang. The potential distributions of A. mgolicus and A. nanus by 2050 in two climate scenarios (RCP4.5 and RCP8.5) were predicted to change little relative to the current potential distribution, but the level of suitability of many areas within the potential distribution was predicted to change substantially. However, suitable areas of habitat for A. mgolicus and A. nanus were predicted to decrease under the higher CO₂ emissions scenario (RCP8.5). Annual average temperature (Bio1), precipitation of wettest month (Bio13), and variation in temperature seasonality (Bio4) were the most important factors contributing to changes in the potential distributions of Ammopiptanthus plants. In the future, Ammopiptanthus plants will make important economic contributions and perform vital ecological service functions in arid and semi-arid regions of northwest China.