A traveling transmission device of a tractor including a transmission case to which power from an engine is inputted via an input shaft, a speed changer transmission section provided inside the transmission case and configured to input power from the input shaft and to speed-change the inputted power and output it, and a rear wheel differential mechanism provided inside the transmission case and configured to input power outputted from the speed changer transmission section and transmit the inputted power to left and right rear wheels. The speed changer transmission section includes a plurality of speed changer sections configured to speed-change power from the input shaft by a gear coupling mechanism and a multiple-disc clutch and output it, and, inside the transmission case, an oil feeding pipe extends upwardly of the speed changer transmission section and a discharge nozzle connects to respective portions of the plurality of speed changer sections.