To provide a valve drive device for a two-cycle gasoline engine to reduce the occurrence of jumping through a simple constitution.

In a valve drive device for a two-cycle gasoline engine formed such that a fuel feed valve 11 arranged at the cylinder head 4 of a two-cycle gasoline engine is mechanically driven by a cam 5 attached on a crank shaft 1, a tappet 61A slid along with rotation of a cam 5 and a valve drive arm 10 to open and close a fuel feed valve 11 are interconnected through an idle roller 12 by means of a wire 8 and an energizing means 13 is provided to stretch one end of the valve drive arm 10 in the direction of a cylinder.