To equalize an amount of air sucked in respective cylinders of a multi-cylinder engine.

In the multi-cylinder internal combustion engine, an electronic control hydraulic system for variable action of an engine suction valve is provided and an indicator for indicating a difference of amount of air sucked by the cylinder of the engine during individual introduction step is provided. The system controls the respective suction valves of the engine by a method of difference to vary a time and an opening step. Thereby, the difference of the amounts of air sucked by the respective cylinder of the engine is minimized.