Abstract: An operation device of a clutch master cylinder including a clutch master cylinder slidably incorporating therein a piston and a clutch lever pivotally supported by a pivot on a lever holder and having a piston operating arm. The clutch lever has a bearing hole formed substantially parallel to the pivot and a rotor is turnably fitted into the bearing hole. A push rod which comes into contact with the piston so as to be able to rock is interconnected to the rotor. To adjust the play stroke of the clutch lever, the length of the push rod is adjustable in one embodiment of the invention. In another embodiment, the pivot is fitted to a shaft hole of the clutch lever and the axis of the pivot is eccentrically disposed with respect to the center of the shaft hole.