A connecting rod apparatus for converting a rotational motion to a reciprocal linear motion by connecting an eccentric portion of a crank shaft to a piston. The connecting rod apparatus has a bushing, a connecting rod and a connecting member. The bushing is rotatably connected with the eccentric portion, and has a sloping side on its outer surface with a predetermined slope in regard to an axis of the eccentric portion. The connecting rod has a piston attachment formed at one end for being connected with a piston pin which is connected with the piston. A connecting portion is formed at another end of the connecting rod and is connected with the bushing in a direction of the axis along the sloping side of the bushing. The connecting member connects the connecting portion and the bushing so that the connecting portion and the bushing can move relative to one another.