Mollusks, arthropods and chordates which were visible to the naked eye were observed and collected in Dongbei and Shuijiang caves of Libo county five times between February and July from 2002 to 2005. Four hundred and forty samples from Dongbei Cave were classified into three phyla, five classes, 10 orders, 20 families and 39 species or groups of species. Four hundred and ninety-eight samples from Shuijiang Cave were classified into three phyla, six classes, 11 orders, 20 families and 25 species or groups of species. Six animal communities were identified in the light belt of the two caves according to their species types and numbers of individuals in the light belt of two cave. The communities which have the highest values of species richness community diversity, maximum diversity, evenness, dominance and community similarity are respectively: B (4.1059), H (2.4716), B (3.3322), E (0.9042), C (0.3442) and A-C (0.5251). The community diversity and correlation of environmental factors were also studied. The temperature, humidity, content of CO 2 and N 2, content of organic matter and some inorganic salts in soil were analyzed by Pearson correlation. The results showed that the content of organic matter in soil is positively related to species number, species richness and maximum community diversity, with correlations of 0.885, 0.909, 0.868 respectively (two-tailed significance test, P≤0.05), and significantly positively related to diversity, with the coefficient of 0.611, (two-tailed significance test, P≤0.1). This suggests that the content of organic matter in soil is one of the important elements influencing the community variation of cave animals. Outside the cave, temperature and humidity are important factors impacting on community diversity. As the temperature in all seasons in the cave is stable and the humidity is always high (above 90%), the temperature and humidity have weak correlation to community diversity in caves.