A variable valve system includes a camshaft in which a first lobe having a first height and a second lobe having a second height that is higher than the first height from a rotational center axis of the camshaft are formed; a first tappet that corresponds to the first lobe and that has a depression negatively formed in one side thereof; a second tappet corresponding to the second lobe and that is inserted into the depression; at least a pin positioned at the first tappet and fixing a position of the second tappet; and a hydraulic pressure control portion that transfers hydraulic pressure into the depression so as to move the second tappet upwards or downwards and to the pin so as to engage or disengage the first tappet with the second tappet.