In a link type variable stroke engine in which a piston, a crankshaft and an eccentric shaft are linked by a linking mechanism, counterweights are provided on the crankshaft so that in a projection view on a plane orthogonal to a rotation axis of the crankshaft, centers of gravity of the counterweights are located on a straight line extending from the rotation axis of the crankshaft in an opposite direction to a direction of a total inertial exciting force when the total inertial exciting force becomes maximum, the total inertial exciting force being obtained by adding inertial exciting forces occurring respectively in movable components of the linking mechanism. Accordingly, it is possible to effectively suppress and lessen inertial exciting force.