Abstract:Dry-hot valley is featured with high temperature, rapid evaporation, and poor vegetation. It is a typical representative of arid ecosystems. In order to understand the response of pteridophytes diversity and population distribution to environmental factors, the distribution patterns of temperature and precipitation at different elevations in Yuanjiang dry-hot valley were established, and the distribution of pteridophytes in dry-hot valley was studied. The results showed that the temperature in Yuanjiang dry-hot valley declined along altitude, whereas precipitation increased. The diversity and population distribution of pteridophytes in Yuanjiang dry-hot valley were strongly differentiated. The distribution of pteridophytes are not associated to temperature but closely related to water supply. Conclusively, the habitat in Yuanjiang dry-hot valley was fragmented due to heterogeneous environmental factors, which accelerates patchy vegetation. Pteridophytes were a certain kind indicator of integrative and continuous living circumstance, while some species could be potential environmental monitors especially for water condition.