[in Chinese with English abstract:] The community structure and species diversity of the dead wood dwelling lichens in forest ecosystem of Altay Two River Sources National Natural Reserve were studied using two‐way indicator species analysis and detrended correspondence analysis methods. The relation between the lichen species distribution pattern and environmental factors were analyzed according to canonical correspondence analysis results. Forty‐three dead wood dwelling lichens species belonging to 20 genera and 14 families of 5 orders were found in this ecosystem. According to the quantitative analysis results, the lichen communities were divided into the following four types: community Ⅰ: Physcia dimidiate+Ph. semipinnata+Phaeophyscia erythrocardia; community Ⅱ: Cladonia subulata+Cl. fimbriata+Cl. humilis; community Ⅲ: Caloplaca cerina+Calicium abietinum+Chaenotheca stemonia; community Ⅳ: Parmeliopsis ambigua+Candelaria concolor+Lecidea elabens. The similarity index of community Ⅰ and Ⅱ was the highest (0.723), and that of communityⅠand Ⅲ (0.609) ranked second; the lowest similarity occurred between community Ⅲ and Ⅳ(0.262). The community Ⅲ holds the highest rank in species diversity (1.954), then community Ⅱ (1.742) and communityⅠ(1.685), while community Ⅳ ranks lowest (0.543). It was found that, the dead wood dwelling lichen species composition and distribution were mainly affected by the factors such as altitude, dead wood decayed degree, canopy density and dead wood volume. Key words: dead wood dwelling lichen, quantitative classification, species distribution pattern, Altay Two River Sources National Nature Reserve.