Functional diversity of soil microbial communities was examined by microbial metabolic diversity (BIOLOG) assays to evaluate the effects of enrofloxacin with different concentrations on soil microbial communities. The results showed that soil microbial metabolic diversity in CK was significantly higher than that in the soils in which the enrofloxacin was added. In BIOLOG assays, the average well colour development (AWCD) and the richness and diversity indices indicated the differences of microbial metabolic diversity. It also indicated that the enrofloxacin significantly affected the sole-carbon-source metabolic ability of soil microbial communities，While low concentration of enrofloxacin (0.01μg/g) significantly affected the metabolic ability of sole-carbon-source, such as α-Ketobutyric Acid, L-Phenylalanine, 1-Erythritol, D-Xylose and so on. The effects of enrofloxacin on functional diversity of soil microbial communities were enhanced with the increasing enrofloxacin concentration. Therefore, the potential effects of enrofloxacin on the soil microbial communities warrant further studies.