A housing for an axle driving apparatus which is partitioned therein through an inner wall into a first chamber for housing therein a hydrostatic transmission and a second chamber for housing therein a drive train for transmitting power outputted from the hydrostatic transmission to axles. An oil filter is disposed between the first chamber and the second chamber. The first chamber and the second chamber are filled with oil which can flow between the first chamber and the second chamber through an oil filter, whereby the volume of oil, which varies as the temperature of the oil in the first chamber rises or lowers, can be adjusted.