To excellently maintain an exhaust gas state with a simple constitution, when remodeled into an engine system for non-gasoline fuel, by using an engine system using gasoline.

This engine control system 1A of gasoline substitute fuel engine uses engine control information outputted from an electronic control unit 10 for controlling an engine by inputting the information to an electronic control unit 11, by extending the electronic control unit 11 for the non-gasoline engine fuel to the engine system having the electronic control unit 10 for the gasoline and using the gasoline. An output signal from an O2 sensor arranged in an exhaust pipe is inputted to the electronic control unit 10 for the gasoline after shaping by a waveform shaping device 6, and is corrected so that the engine control information outputted from the electronic control unit 10 is adapted to the electronic control unit 11 for non-gasoline fuel.