Abstract: Rural sewage mixed with rainwater always has the characteristics of low pollution and low carbon-nitrogen ratio. Due to the lack of carbon source, the total nitrogen (TN) is difficult to remove and cannot meet the discharge value when rural sewage is treated by biological method. The broken Arundo donax pieces were used as the filter media and carbon source for the anoxic column of the anoxic/oxic (A/O) biofilter (2 ^#) to enhance the nitrogen removal for rural sewage, and the gravel-filling A/O biofilter (1^#) was set up as the control, in order to study the nitrogen removal enhancement of Arundo donax. The denitrifying microbial communities in the system were also analyzed by the scanning electron microscopy (SEM) and real-time fluorescence quantitative polymerase chain reaction (qPCR). The results showed: when the influent COD_Cr, ammonium ( ${\mathrm{NH}}_4^{+}$ -N), TN and phosphate ( ${\mathrm{PO}}_4^{3-}$ -P) concentrations were (79.47±14.21), (34.49±2.08), (34.73±3.87)and (2.38±0.46) mg/L, respectively, their removal rates of 1^# and 2^# biofilters were 88%±7% and 86%±6%, 90%±2% and 97%±7%, 38%±13% and 65%±9%, 27%±13% and 40%±18% , respectively, at the 10 h hydraulic retention time. The biofilter with Arundo donax as the anoxic column filter media could significantly enhance the removal rates of ${\mathrm{NH}}_4^{+}$ -N, TN and ${\mathrm{PO}}_4^3$ -P of A/O biofilter. The microorganisms on 1^# and 2^# biofilters anoxic column medias were mainly composed of short bacilli, and the abundance of denitrification genes and anaerobic ammonium oxidation (ANAMMOX) genes in 2^# anoxic column was higher than those in 1^# anoxic column.