A work vehicle comprising: - a protective frame including a first frame and a second frame rotatably coupled with an upper part of the first frame; and - an assist mechanism that assists a rotating operation of the second frame, wherein - the first frame is a lower frame that is fixed on a rear side of a seat; - the second frame is an upper frame coupled with the upper part of the lower frame through a rocking shaft to be capable of rocking in a front-rear direction; - the upper frame is made to be displaceable by a rocking operation to an upright position in which the upper frame stands up above the lower frame, and to a laid-down position in which the upper frame is folded with respect to the lower frame; and - the assist mechanism includes an urging mechanism capable of urging the upper frame toward a side of the upright position in a rocking direction of the upper frame, characterized in that the assist mechanism is configured such that - in a state in which the upper frame is located on a side of the laid-down position with respect to a boundary position between the upright position and the laid-down position, a rocking force applied to the upper frame toward the upright position by the urging mechanism is smaller than the rocking force applied to the upper frame toward the laid-down position due to an own weight of the upper frame, and - in a state in which the upper frame is located in a predetermined range from the boundary position on the side of the upright position, the rocking force applied to the upper frame toward the upright position by the urging mechanism is larger than the rocking force applied to the upper frame toward the laid-down position due to the own weight of the upper frame. - a protective frame including a first frame and a second frame rotatably coupled with an upper part of the first frame; and - an assist mechanism that assists a rotating operation of the second frame, - the first frame is a lower frame that is fixed on a rear side of a seat; - the second frame is an upper frame coupled with the upper part of the lower frame through a rocking shaft to be capable of rocking in a front-rear direction; - the upper frame is made to be displaceable by a rocking operation to an upright position in which the upper frame stands up above the lower frame, and to a laid-down position in which the upper frame is folded with respect to the lower frame; and - the assist mechanism includes an urging mechanism capable of urging the upper frame toward a side of the upright position in a rocking direction of the upper frame, - in a state in which the upper frame is located on a side of the laid-down position with respect to a boundary position between the upright position and the laid-down position, a rocking force applied to the upper frame toward the upright position by the urging mechanism is smaller than the rocking force applied to the upper frame toward the laid-down position due to an own weight of the upper frame, and - in a state in which the upper frame is located in a predetermined range from the boundary position on the side of the upright position, the rocking force applied to the upper frame toward the upright position by the urging mechanism is larger than the rocking force applied to the upper frame toward the laid-down position due to the own weight of the upper frame.