20% Butanol-Gasoline blend was mixed based on volume ratio with 93# unleaded gasoline.The effects of the butanol-gasoline blended fuel on the engine performance were investigated through experiments.The experiment results have shown that,without any modification of the engine,the 20% Butanol-gasoline blended fuel has little effect on the engine performance compared with the original 93# gasoline fuel.The performance at low speed is even better.And the HC and CO emissions are reduced significantly.