An internal combustion engine comprises two intake valves per cylinder, and also comprises a stationary cam for driving one of the intake valves with lift characteristics in which the open timing is near top dead center, a variable valve mechanism in which the lift characteristics can be varied according to the operating state of the engine from small lift characteristics in which the actuating angle and lift amount are small due to the stationary cam, and large lift characteristics in which the actuating angle and lift amount are large due to the stationary cam, and a variable cam which is provided with the variable valve mechanism and which drives the other intake valve. In the case of small lift characteristics, the variable valve mechanism sets the lift characteristics of the variable cam, so that the open-valve timing is to the retarded side of the stationary cam.