In order to know the composition of bacterial community in the pit mud of Luzhou-flavor liquor，and to study further the relationship between microbial diversity and liquor characteristics，traditional microbial classification and identification methods were carried out to analyze the culturable facultative anaerobes in the mud samples from both bottoms and walls of the pits of different ages.The bacterial strains were identified to genus according to their morphological，physiological and biochemical characteristics.Counted by using dilution-plate method，the total amount of bacterial colonies in the bottom of older pit was found to be the highest，reaching to 3.98 10³cfu/g mud.While the least was found in the wall of younger pit，only 0.24 10³cfu/g mud.So the older the pit mud is，the bigger the bacterial community is.The result of identification showed that most of the strains isolated from pit mud belong to the genera Bacillus and Sporolactobacillus，those belong to genera Mycobacterium，Pseudomonas，Microbacterium，Corynebacterium，Flavobacterium and Clostridium were also existent.