Abstract: The relationships of 13 species of Polytrichaceae in 30 sites in main ecosystems in Changbai Mountains with environmental factors were studies by canonical correspondence analysis (CCA). The results showed that there are niche differination among the 13 taxa in altitude, soil sand content, water content, acidity and light. The ecological similarities are higher among Polytrichum sphaerothecium, Polytrichastrum alpinum var. brevifolium in altitude, Polytrichastrum ohioense, Polytrichastrum formosum, Polytrichum piliferum, Polytrichum juniperinum in light, Polytrichum commune and Polytrichum juniperinum ssp. strictum in soil water content and acidity.

Key words: Polytrichaceae, Canonical Correspondence Analysis, Niche