The aim of the work is to investigate performance and exhaust gas emission of spark ignition generator set fueled with gasoline, biogas, and liquefied petroleum gas (LPG). Engine speed, brake power, torque, brake-specific fuel consumption (BSFC), brake thermal efficiency (BTE) CO2, and HC in exhaust gas of the generator are compared for each fuel at variation electric load. The result indicates engine speed decreases as increasing electric load for all fuel. The performances of the generator in terms of brake power and torque are almost similar when fed by gasoline, biogas, or LPG. From measured CO2 and HC in exhaust gas, gasoline burn more effective during combustion stage in present work. However, in terms of BSFC and BTE, biogas fuel gives better result than either gasoline or LPG.