In an internal combustion engine, a variable compression ratio mechanism able to change a mechanical compression ratio, a variable valve timing mechanism able to control the closing timing of the intake valve, and an electronic control unit that predicts the temperature of the catalyst arranged in the engine exhaust passage are provided. When it is predicted that the temperature of the catalyst will fall to less than the activation temperature, the actual expansion ratio is lowered while maintaining the actual compression ratio the same or while increasing the actual compression ratio.