PROBLEM TO BE SOLVED: To improve the working efficiency of a working vehicle by preventing a filter from being clogged to prevent the lowering of the radiator/engine cooling efficiency.SOLUTION: This driving portion structure of a working vehicle includes: a cooling fan (22) provided inside of the radiator (24) the filter (29) provided outside of the radiator (24) to filter outside air to be sucked by the cooling fan (22) a wind shielding plate (30) provided between the radiator (24) and the filter (29) to shield the outside air to be sucked toward the radiator (24) a ventilation part (31) formed at a part of the wind shielding plate (30) to allow ventilation a fan (41) for blowing air outside of the wind shielding plate (30) through the ventilation part (31). The wind shielding plate (30) is configured to freely move in a direction for changing the amount of superposition of the wind shielding plate (30) with the radiator (24) in the direction for sucking the outside air.
