Abstract: A transmission control system includes an up-shifting operation device, a clutch actuator, a shift actuator and a CPU. The CPU controls the clutch actuator to start a disconnection operation of a clutch at a time point when movement of an operation lever of the up-shifting operation device is started. Moreover, the CPU controls the clutch actuator to complete the disconnection operation of the clutch at a time point when the movement of the operation lever is finished. Then, the CPU shifts a gear position of a transmission by controlling the shift actuator.