Abstract: A variable valve system according to the present invention comprises a solid cam having a cam profile continuously varying in axial direction of a cam shaft in a range from lower revolutions to higher revolutions of an internal combustion engine, a displacement device for axially displacing the solid cam continuously or stepwise, and an arm that swings in accordance with the cam profile of the solid cam to open and close a valve. The arm is provided with a cam contacting mechanism that is formed of a seat and a cam contacting portion. The cam contacting portion is fitted into the seat such that the cam contacting portion contacts the solid cam and follows changes in inclination of a tangential line defined by the cam contacting portion and the solid cam when the solid cam rotates.