To shorten the time needed for determination of biological oxygen demand(BOD),this study reports a method that can be used for rapid measurement of BOD in domestic organic wastewater based on air cathode microbial fuel cell technology.Testing results indicated that when glucose was used as single organic substrate,the relationship between voltage output and glucose concentration followed Monod equation.When glucose concentration(BOD) was less than 100 mg/L,good linear relationship between voltage and glucose concentration was obtained.It’s merely needed about 10 h to determine BOD in effluent from aeration grit chamber,primary clarifier and aeration tank in wastewater treatment plant by air-cathode microbial fuel cell,which effectively shortens the measurement time.