Renewable algae biomass, Scenedesmus obliquus, was used as substrate for generating electricity in two chamber microbial fuel cells (MFCs). From polarization test, maximum power density with pretreated algal biomass was 102 mW·m^-2 (951 mW·m^-3) at current generation of 276 mA·m^-2. The individual electrode potential as a function of current generation suggested that anodic oxidation process of algae substrate had limitation for high current generation in MFC. Total chemical oxygen demand (TCOD) reduction of 74% was obtained when initial TCOD concentration was 534 mg·L^-1 for 150 h of operation. The main organic compounds of algae oriented biomass were lactate and acetate, which were mainly used for electricity generation. Other by-products such as propionate and butyrate were formed at a negligible amount. Electrochemical Impedance Spectroscopy (EIS) analysis pinpointed the charge transfer resistance (112 ?) of anode electrode, and the exchange current density of anode electrode was 1214 nA·cm^-2.