An axle driving apparatus which is so constructed that an input pulley for engine power is set lower in mounting position with respect to the axis of a driving axle so s to enable the platform of a vehicle to be lowered. The engine position lowers to promote miniaturization, a lower center of gravity and running stability of the vehicle. For maintenance of the transmission for driving the axle, the entire axle driving apparatus need not be removed from the frame of the vehicle. A bearing for supporting the axle to the casing is held with exact dimensional precision so as not to cause a backlash on the axle, to thereby prolong the life span of the bearing. The axle is ensured to be sealed, the number of mounting bolts for the casing need not be increased in order to improve rigidity, and the casing is strong so that the assembly time for the axle driving apparatus is minimized.