To provide a system for varying valve variation quantity of all the intake valves of a plurality of cylinders wholly by a single variable valve mechanism, in which torque irregularity between the cylinders due to intake air quantity irregularity between two intake valves of the same cylinder can be corrected.

Normally, intake air quantity irregularity ratio between the cylinders is determined to control lift quantity for each cylinder by driving a variable valve lift mechanism at high speed at every prescribed timing based on the intake air quantity irregularity ratio between the cylinders for controlling the intake air quantity for each cylinder so as to correct the intake air quantity irregularity between the cylinders. In a case where torque irregularity between the cylinders exceeds a tolerable range during control to correct the intake air quantity irregularity between the cylinders, torque irregularity ratio between the cylinders is determined to drive the variable lift mechanism at high speed at every prescribed timing based on the torque irregularity ratio between the cylinders for controlling the lift quantity for each cylinder. Torque can thus be controlled for each cylinder to correct torque irregularity between the cylinders.