Abstract: In order to explore factors affecting structure of enchytraeid community, a study was carried out in the Mengshan Mountain in September, 2011. In the study, a total of 513 individuals were collected and identified, belonging to 15 species of 4 genus; Fridericia juveniles, Fridericia dianchiensis, Henlea sp6, Enchytraeus juveniles were the dominant species. One-Way ANOVA analysis was performed to compare sampling stations in density of enchytraeid, and found the stations followed the order of S6 > S1, S2 and S4 > S3, S5 and S7. And it was also found that Margalef's diversity index, Shannon-Wiener diversity index and species richness was positively related to altitude. Non-matric multidimentional scaling 2-dimensional ordination of specific composition reveals that S4 and S7 were quite similar in specific composition of their enchytraeid communities and S2 and S5 differed sharply from other stations in this aspect. Non-matric multidimentional scaling ordination of density indicates that similarity existed between S4 and S7 and between S1，S2，and S6 in structure of enchytraeid community. Percentage similarity analysis shows that S1, S5, S6 and S7 were quite similar, and S2, S3 and S4 were not so much between each other. Characteristics of microhabitats were the main factor affecting similarity in enchytraeid density and community structure. Canonical correspondence analysis divided the community into 4 species groups. Contents of soil water, soil organic matter, total nitrogen, total phosphorus, ammonia nitrogen, nitrate nitrogen and potassium are the major factors affecting structure of the enchytraeid community.

Key words: enchytraeid, Mengshan Mountain, biodiversity, community structure