Abstract: Grimmia and Racomitrium are two important genera of the family Grimmiaceae (Musci,Bryophyta).To predict and compare their potential distribution regions in relation to climatic conditions in China,and thereby help their conservation and subsequent field investigations,we modeled the geographical distribution at the genus level by using a maximum entropy algorithm modeling program (MaxEnt) based on 172 presence-only data for Grimmia and 181 data for Racomitrium,as well as 19 bioclimatic variables.We found Grimmia had higher habitat suitability in Zhejiang (0.7099,integrated habitat suitability index),Jiangsu (0.6212),Beijing (0.5987),Tianjin (0.5648),Yunnan (0.5532),Liaoning (0.5515),Taiwan (0.5422),Anhui (0.5398),and Jilin (0.4945),while Racomitrium had higher habitat suitability in Zhejiang (0.889),Shanghai (0.6564),Hong Kong (0.5897),Taiwan (0.5858),Guizhou (0.5354),Hubei (0.5039),Yunnan (0.4885),Chongqing (0.4871),Jiangsu (0.4793),and Anhui (0.4552).Comparison between the predicted distribution of Racomitrium and that of Grimmia showed that Racomitrium had higher distribution probability in Hong Kong,Chongqing,Guizhou,Guangdong,Guangxi,Hubei,Hainan,and Taiwan than Grimmia,similar distribution probability to that of Grimmia in Jiangxi,Fujian,Hunan,and lower than Grimmia in the other provinces (municipality autonomous regions).Grimmia belonged to the typical moderate geographical element,mainly in the high altitude and cold districts.