In a link type variable stroke engine in which a piston, a crankshaft and an eccentric shaft are linked by a linking mechanism, an oil supply hole for supplying lubricating oil to a position between a connection tubular part of a sub connecting rod and a crank pin is provided in an upper portion of the connection tubular part at a position which is deviated from a direction of application of maximum load applied from the crank pin to an inner surface of the connection tubular part by maximum in-tube pressure, and which is immediately behind a point of application of the maximum load along a direction in which the crank pin rotates relative to the sub connecting rod. Accordingly, it is possible to prevent leak of oil from the oil supply hole and thereby reliably lubricating the position between the connection tubular part of the sub connecting rod and the crank pin by a splash lubrication system.