Fundamental subjects on application of pure methanol to conventional spark ignition engines were investigated. Thermal efficiency increased. The reason is that the combustion pressure does not decrease while the temperature of the combustion gas decreases, because the moles of the methanol burned gas increase compared to those of gasoline. Having an anti-knock property, compression ratio can be raised, however, preignitlon easily ocurrs. Unburned fuel and aldehyde sampling methods were examined. These emissions were exhausted to a greater degree than in the case of gasoline. Low evaporative emission was emitted with EFI system. Cold startability is acceptable using a dual fuel system. There Was no trouble in driveability in hot weather, and materials used in the tests were shown.Methanol would be an attractive alternative fuel for automotive use, however, problems are still remaining.