Diversity and species composition of microorganism assemblages on the leaves of 6 species of bamboo located in Sichuan Province were investigated based on the traditional forest pathology and modern molecular biology methods. The results show that fungi and bacteria are the large groups on the leaves. Although the bacterial quantity is larger than the amount of fungi, but the species of fungus are much more abundant than bacterial species. There are large differences among the six bamboo species about the microbial community structure. Ya′an area is obviously higher than that of Yibin and Luzhou area. All kinds of groups present seasonal differences which can been seen from the separating frequency.Cladosporium sp.,Saccharomyces sp.,Arthrinium sp.,Pleosporales sp.,Bacillus sp. and Pseudomonas sp. are the species existing persistently on the leaves. Finally, some biocontrol strains and beneficial microbes and even potential pathogenic microorganisms are obtained from bamboo leaves. In conclusion, this study provides the basis for the screening of bio-control strains, developing microorganism resource and preventing the diseases.