To enhance the stiffness of motor-attached portions for attaching electric motors for controlling the outputs of HST (hydrostatic transmission)s.

This combine harvester transmission in which right HST 36 and left HST 38 for driving a pair of right and left crawler travelers 12R, 12L to do the straight travel or turning travel of the machine body 14 are attached to the sidewalls of a mission case 35 is characterized by adjacently disposing the right HST 36 and the left HST 38, attaching the right HST 36 and the left HST 38 in a state nipped with a bracket 70 having a U-shaped holder 69, and further integrally building in a right electric motor 66 and a left electric motor 68 for independently controlling the outputs of the right HST 36 and the left HST 38 in the bracket 70 to enhance the stiffness of the motor-attached portion.