A work vehicle comprising: a first clutch mechanism of a wet type configured to engage/disengage transmission of a traveling driving power transmitted from a first shaft to a traveling mechanism (1,2); a second clutch mechanism of a wet type configured to engage/disengage transmission of a traveling driving power transmitted from a second shaft to the traveling mechanism (1,2); an intermediate rotational member rotatable relative to the first shaft due to a drag torque associated with rotation of the first shaft; and a coupling portion configured to transmit a rotational power of the intermediate rotational member to an output portion of the second clutch mechanism, characterized in that the work vehicle further comprises: a first planetary gear speed changer device for speed-changing traveling driving power and transmitting the resultant power to the first shaft; a second planetary gear speed changer device for speed-changing traveling driving power and transmitting the resultant power to the second shaft; the first clutch mechanism (C 1) being configured to transmit, under its transmission engaging state, the driving power of the first shaft to the traveling mechanism (1,2) as a forward traveling driving power; the second clutch mechanism including a forward traveling clutch section (C2f) configured to transmit, under its transmission engaging state, the driving power of the second shaft to the traveling mechanism (1,2) as a forward traveling driving power and a reverse traveling clutch section (C2r) configured to transmit, under its transmission engaging state, the driving power of the second shaft to the traveling mechanism (1,2) as a reverse traveling driving power; and the second clutch mechanism further including a reverse traveling output gear configured to output the reverse traveling driving power from the reverse traveling clutch section (C2r), so that with meshing of the reverse traveling output gear with a reverse traveling transmission gear, the reverse traveling driving power is transmitted to the traveling mechanism (1,2). a first clutch mechanism of a wet type configured to engage/disengage transmission of a traveling driving power transmitted from a first shaft to a traveling mechanism (1,2); a second clutch mechanism of a wet type configured to engage/disengage transmission of a traveling driving power transmitted from a second shaft to the traveling mechanism (1,2); an intermediate rotational member rotatable relative to the first shaft due to a drag torque associated with rotation of the first shaft; and a coupling portion configured to transmit a rotational power of the intermediate rotational member to an output portion of the second clutch mechanism, characterized in that the work vehicle further comprises: a first planetary gear speed changer device for speed-changing traveling driving power and transmitting the resultant power to the first shaft; a second planetary gear speed changer device for speed-changing traveling driving power and transmitting the resultant power to the second shaft; the first clutch mechanism (C 1) being configured to transmit, under its transmission engaging state, the driving power of the first shaft to the traveling mechanism (1,2) as a forward traveling driving power; the second clutch mechanism including a forward traveling clutch section (C2f) configured to transmit, under its transmission engaging state, the driving power of the second shaft to the traveling mechanism (1,2) as a forward traveling driving power and a reverse traveling clutch section (C2r) configured to transmit, under its transmission engaging state, the driving power of the second shaft to the traveling mechanism (1,2) as a reverse traveling driving power; and the second clutch mechanism further including a reverse traveling output gear configured to output the reverse traveling driving power from the reverse traveling clutch section (C2r), so that with meshing of the reverse traveling output gear with a reverse traveling transmission gear, the reverse traveling driving power is transmitted to the traveling mechanism (1,2). a first planetary gear speed changer device for speed-changing traveling driving power and transmitting the resultant power to the first shaft; a second planetary gear speed changer device for speed-changing traveling driving power and transmitting the resultant power to the second shaft; the first clutch mechanism (C 1) being configured to transmit, under its transmission engaging state, the driving power of the first shaft to the traveling mechanism (1,2) as a forward traveling driving power; the second clutch mechanism including a forward traveling clutch section (C2f) configured to transmit, under its transmission engaging state, the driving power of the second shaft to the traveling mechanism (1,2) as a forward traveling driving power and a reverse traveling clutch section (C2r) configured to transmit, under its transmission engaging state, the driving power of the second shaft to the traveling mechanism (1,2) as a reverse traveling driving power; and the second clutch mechanism further including a reverse traveling output gear configured to output the reverse traveling driving power from the reverse traveling clutch section (C2r), so that with meshing of the reverse traveling output gear with a reverse traveling transmission gear, the reverse traveling driving power is transmitted to the traveling mechanism (1,2).