Abstract: The effects of complex compounds in the wastewater as substrate on the electricity generation performance of MFC were studied in this paper with the same concentration of sodium acetate, glucose, sucrose, D-xylose and soluble starch as substrates of MFC. Under the condition of the same concentration of 8 g/L, the MFC with sodium acetate had internal resistance 64 ?, the maximum volume power density was 3.7 W/m3；The MFC with glucose had internal resistance of 84 ?, the maximum volume power density was 2.67 W/m3, D-xylose voltage had the internal resistance of 167 Ω, maximum power density 1.37 W/m3; sucrose had internal resistance of 68.3 Ω, maximum power density of 2.4 W/m3; the resistance and maximum power density of MFC with starch were 236 Ω and 136 W/m3, respectively. The results showed that MFC could generate the electricity with different organic material. And at the same condition, the simpler the organic compound construction was, the smaller the internal resistance was, the higher the output power was.