Abstract: The mixer of fosfomycin degrading bacteria was added into cyclic activated sludge system (CASS) reactor to treat the effluent from an anaerobic baffled reactor which was fed with pharmaceutical wastewater. The COD_Cr, NH₄⁺-N and TP removal efficiencies were studied, and the comparison between CASS reactor with and without inoculation was carried out. The results showed that when the reactor C2 was inoculated with fosfomycin degrading bacteria, and with the average COD_Cr of 1 101.4 mg/L，average NH₄⁺-N of 134.7 mg/L, average TP of 22.1 mg/L in the influent, the COD_Cr, NH₄⁺-N and TP of effluent were 203.7, 12.6 and 3.2 mg/L, respectively. Accordingly, the average removal efficiency of COD_Cr, NH₃-N and TP was 81.57%, 90.67% and 85.44%, respectively. Comparatively, the average removal efficiency of COD_Cr, NH₃-N, TP of the reactor C1 that was not inoculated with fosfomycin degrading bacteria was 66.91%, 84.30% and 67.41%. Thus the reactor C2 inoculated with fosfomycin degrading bacteria showed better COD_Cr, NH₃-N, TP removal efficiencies than reactor C1. The main fluorescent materials in the influent were identified as aromatic protein substances and soluble microbial products based on the three-dimensional fluorescence spectra analysis. They were removed obviously after inoculated with fosfomycin degrading bacteria.