Constructing air-cathode single-chamber microbial fuel cell(MFC) which use the aging landfill leachate as substrate, to study the influence of different electrode surface area on microbial fuel cells in terms of the electricity productivity and treatment effects of aging landfill leachate. The results illustrate that for three sets of MFCs with the area of anode and cathode being 7.065/7.065, 12.56/7.065 and 12.56/3.14 cm2, the output voltage is 105, 160 and 50 mV, respectively, with the maximum electric power density of 33.7, 96.4 and 5.7 mW/m3, the resistance of 577.6, 433 and 914 Ω, and COD removal rate of 21.4%, 18.5% and 47.6%. The ammonia removal rates for three sets of MFCs are 58.3%, 73.9% and 34.2%, respectively. As the pH value of landfill leachate increases, the conductivity decreases. © 2020, Solar Energy Periodical Office Co., Ltd. All right reserved.