An internal combustion engine provided with a variable compression ratio mechanism able to change a mechanical compression ratio and a variable valve timing mechanism able to individually control the opening timing and closing timing of the intake valve. At the time of engine low load operation, the maximum expansion ratio is obtained by making the mechanical compression ratio maximum and, while the mechanical compression ratio is made maximum, the opening timing of the intake valve is maintained at a target opening timing of substantially intake top dead center in the noninterference region where no interference between the valve and the piston occurs.