To evaluate the effects of ciprofloxacin (CIP) residues on the microbiological characteristics of soil, the microbial biomass carbon (MBC) and carbon鄄source metabolic functions of the soil microbial communities exposed to CIP were studied by the method of chloroform fumigation extraction and Biolog technology. The results showed that the content of MBC of groups treated with CIP (w CIP 逸 0. 1滋g / g) were significantly distinguished from that of CK, and they were decreased with the increasing concentration of CIP in soil, the content of MBC in soil exposed to 100滋g / g CIP decreased 58. 69%. Moreover, the carbon鄄source metabolic functions of the soil microbial communities exposed to CIP significantly decreased, too. Under the application of CIP, the microbial utilization rate of carbon sources, including carbohydrates,