A transmission device for a hybrid vehicle including: a plurality of shift dog clutches each arranged to selectively engage the movable side gear of one of the shift gear rows with the other of the main shaft and the counter shaft; a main clutch disposed between the internal combustion engine and the main shaft; a first motor gear disposed to be raced with respect to a motor output shaft connected to the motor, and constantly interlocked with the main shaft; a second motor gear disposed to be raced with respect to the motor output shaft, and constantly interlocked with the counter shaft; a motor dog clutch arranged to selectively engage one of the first and second motor gears with the motor output shaft; and a controller configured to control actuations of the shift dog clutch, the main clutch, and the motor dog clutch.