To prevent a body attitude from being rolled from side to side in case of starting by performing a reduction in operating force and an improvement in operability of an on-lever by the thumb of hand gripped on an operating part.

In this clutch shifting device of traveling farm machinery, which connects a main clutch lever 17 to a main clutch via a fulcrum over link 28 and a clutch wire 29, and installs an on-lever 22 parallelly in a body inner side of an operating part 15a of a steering handle 15, operating this on-lever 22 with the thumb of hand gropped on this operating part 15a, and makes the main clutch lever 17 into input operation, a rotor 31 is attached to a shaft 30 to be clamped to the main clutch lever 17, while a lever arm 32 to be made contact with this rotor 31 is locked to the on-lever 22, and acting length from a fulcrum shaft 33 of the lever arm 32 to the rotor 31 is made so as to make it become successively smaller during the on-operation of the on-lever 22, and simultaneously at the point of fulcrum over time when the operating force of the main clutch lever 17 becomes necessitated at the maximum, the acting length of the lever arm 32 is made so as to be minimized.