Bryophytes are the main understory dominant species in forest areas of Qilian Mountain,which play an important role in keeping a humid environment,surface runoff modulation and water sources holding.We conducted a field investigation of bryophytes along altitude gradient,and made a detailed bryophytes taxonomy.Based on the characteristics of bryophytes distribution,partitioning them into different distribution zones,including low altitude bryophytes distribution zones,arboreal bryophytes distribution zones and alpine bryophytes distribution zones.The water-holding capacity of bryophytes varied with its layers' thickness,and reached the maximum 519.44% when the layers is 7.4 cm thick.In the forest areas,bryophytes water content showed a downtrend from May to September,with maximum occurred in May and minimum in July,moreover,soil with bryophytes coverage showed lower evaporation than that without bryophytes coverage