Changing the advanced ignition angle by rotating the distributor housing, the effects of ignition timing on M20 and E20（20% methanol and ethanol by volume）alcohol-gasoline blends fuelled SI engine performance and exhaust emissions were experimentally investigated. The experimental results show that, compared with gasoline, M20 and E20 fuel blends advance the maximum burning pressure point by 1°CA (crank angle) and 0.5°CA, and the optimal ignition timing by about 2°CA and 1°CA respectively. The effects of ignition timing on engine power, fuel economy and exhaust emissions characteristics of two blends are similar. With the advance of ignition timing, engine power and brake torque increase, brake-specific energy consumption (BSEC, Bsec) decreases and the thermal efficiency is improved, however, CO, HC and NOx emissions are enhanced.