A working vehicle comprising: a main change speed mechanism configured to transmit a rotating power, generated by a power source; a first auxiliary change speed mechanism configured to transmit the rotating power, transmitted through the main change speed mechanism, to drive wheels (2, 3); a second auxiliary change speed mechanism configured to transmit the rotating power, transmitted through the main change speed mechanism, to the drive wheels (2, 3); a first lever configured to operate the first auxiliary change speed mechanism to perform a first auxiliary shift operation, the first lever being operable by an operator; and a second lever configured to operate the second auxiliary change speed mechanism to perform a second auxiliary shift operation, the second lever being operable by the operator, characterized by a regulating mechanism configured to: limit the second auxiliary shift operation to maintain the neutral state of the second auxiliary change speed mechanism when the rotating power is transmitted by the first auxiliary change speed mechanism; and limit the first auxiliary shift operation to maintain the neutral state of the first auxiliary change speed mechanism when the rotating power is transmitted by the second auxiliary change speed mechanism, wherein: the first auxiliary change speed mechanism is activated when the second auxiliary change speed mechanism in a neutral state; and the second auxiliary change speed mechanism is activated when the first auxiliary change speed mechanism is in the neutral state. a main change speed mechanism configured to transmit a rotating power, generated by a power source; a first auxiliary change speed mechanism configured to transmit the rotating power, transmitted through the main change speed mechanism, to drive wheels (2, 3); a second auxiliary change speed mechanism configured to transmit the rotating power, transmitted through the main change speed mechanism, to the drive wheels (2, 3); a first lever configured to operate the first auxiliary change speed mechanism to perform a first auxiliary shift operation, the first lever being operable by an operator; and a second lever configured to operate the second auxiliary change speed mechanism to perform a second auxiliary shift operation, the second lever being operable by the operator, characterized by a regulating mechanism configured to: limit the second auxiliary shift operation to maintain the neutral state of the second auxiliary change speed mechanism when the rotating power is transmitted by the first auxiliary change speed mechanism; and limit the first auxiliary shift operation to maintain the neutral state of the first auxiliary change speed mechanism when the rotating power is transmitted by the second auxiliary change speed mechanism, limit the second auxiliary shift operation to maintain the neutral state of the second auxiliary change speed mechanism when the rotating power is transmitted by the first auxiliary change speed mechanism; and limit the first auxiliary shift operation to maintain the neutral state of the first auxiliary change speed mechanism when the rotating power is transmitted by the second auxiliary change speed mechanism, wherein: the first auxiliary change speed mechanism is activated when the second auxiliary change speed mechanism in a neutral state; and the second auxiliary change speed mechanism is activated when the first auxiliary change speed mechanism is in the neutral state. the first auxiliary change speed mechanism is activated when the second auxiliary change speed mechanism in a neutral state; and the second auxiliary change speed mechanism is activated when the first auxiliary change speed mechanism is in the neutral state.