To provide a variable valve mechanism in which a lift can be continuously changed by a simple mechanism.

The variable valve mechanism comprises a rocker arm 3 swinging with rotation of a cam 2, and a valve 4 provided at one end of the rocker arm 3, and opened/closed by swing of the rocker arm 3. The rocker arm 3 is supported by a fixed shaft 5 for fixing a position in the orthogonal direction to the rocking movement of the rocker arm 3, and a variable shaft 6 provided movably in the orthogonal direction to the rocking movement of the rocker arm 3. The variable shaft 6 is inserted in a slot 8 for the variable shaft 6 extending in the orthogonal direction to the rocking movement for the rocker arm 3. The variable shaft 6 is provided with a variable-shaft-moving means which allows the variable shaft 6 to move in the slot 8.