Macromitrium and Orthotrichum are two largest genera in the Orthotrichaceae (Bryopsida) family. Macromitrium are distributed across tropical zones, while Orthotrichum are distributed throughout temperate zones. Based on eleven bioclimatic variables modeled under recent (1950-2000), 2050, and 2070 RCP45CO₂ emission scenarios, 66 geographical records of Orthotrichum, and 131 records of Macromitrium in China, this paper used the algorithm of maximum entropy (Maxent) to predict the potential Chinese distributions of these two genera in 2050 and 2070. The eleven bioclimatic variables are: mean diurnal temperature range;temperature seasonality;annual temperature range;the highest temperature of the warmest month;mean temperatures of the driest quarter and coldest quarter;precipitations of the wettest month, driest month, warmest quarter, and coldest quarter;and precipitation seasonality. Thirty-eight nature reserves were selected and an integrated climate suitability index was calculated for each of them under different climate conditions. These 38 reserves are: Wuyishan (Fujian);Qilianshan (Gansu);Nanling (Guangdong);Huaping and Shiwandashan (Guangxi);Fanjingshan and Leigongshan (Guizhou);Jianfengling (Hainan);Wutaishan (Hebei);Jigongshan and Xiaoqinling (Henan);Shennongjia and Xingdoushan (Hubei);Changbaishan (Jilin);Lushan (Jiangxi);Baishilizi and Yiwulvshan (Liaoning);Daheishan (Inner Mongolia);Helanshan (Ningxia);Sanjiangyuan (Qinghai);Yuntaishan (Shandong);Lishan, Luyashan, Foping, and Taibaishan (Shaanxi);Gonggashan and Wolong (Sichuan);Ailaoshan, Daweishan, and Nabanhe (Yunnan);Fengyangshan, Gutianshan, Jiulongshan, Putuoshan, Qingliangfeng, Xitianmushan, and Wuyanling (Zhejiang);and Dabashan (Chongqing). The corresponding cumulative value for an omission error of 10% was selected as a distribution threshold. The primary results were: (1) The suitable bioclimatic habitats for Macromitrium and Orthotrichum would shrink considerably with predicted climate warming. The potential distribution range of Macromitrium in China would declime from 31.5% under recent climate condition to 12.23% under 2070 climate condition, while that of Orthotrichum would declime from 65.81% to 44.94%. The negative effects of climatic warming on the potential distribution would be greater for Macromitrium than for Orthotrichum;(2) All of the nature reserves, except for Helanshan and Qilianshan, had suitable niches for Macromitrium under the recent climatic scenario. Under the 2070 predicted climate scenario, the potential distribution of Macromitrium would not include Jigongshan, Yuntaishan, Putuoshan, Jiulongshan, Gutianshan, Daheishan, Luyashan, Lushan, Yiwulvshan, Huaping, Baishilazi, Wutai, Lishan, Xiaoqinling, Foping, Changbaishan, Fanjingshan, Leigongshan, and Wuyishan (half of the 38 nature reserves in this study);and (3) All of the nature Reserves, except Jianfengling, had suitable niches for Orthotrichum under the recent climate scenario. By 2070, the weather adaptation indices for Orthotrichum in all of the 38 reserves would be lower than those under the current conditions. According to our predictions for 2070, Orthotrichum would be excluded from the reserves in Huaping, Lushan, Shiwandashan, Jigongshan, Taishan, Putuoshan, Xitianmushan, Gutianshan, Jiulongshan, Wuyishan, Fanjingshan, Yiwulvshan, Xiaoqinlingshan, and Foping.