A work vehicle comprising: an engine ; a hydraulic pump driven by the engine ; a work implement driven by hydraulic fluid discharged from the hydraulic pump ; a travel device driven by the engine ; an accelerator operating member for changing an engine rotation speed; a work implement operating member for operating the work implement ; a control unit for causing a speed of the work implement to increase by causing the engine rotation speed to increase when an operation amount of the work implement operating member is increased; and a power transmission device that has an input shaft , an output shaft , and a motor (MG1, MG2), the power transmission device transmitting driving power from the engine to the travel device ; wherein the power transmission device is configured so that a rotation speed ratio of the output shaft with respect to the input shaft is changed by changing a rotation speed of the motor (MG1, MG2), the control unit controls a tractive force of the vehicle by controlling an output torque of the motor (MG1, MG2), the control unit determines a required tractive force which is a target tractive force of the travel device on the basis of the operation amount of the accelerator operating member and controls the output torque of the motor (MG1, MG2) so that the tractive force of the vehicle becomes the required tractive force, and the control unit is characterized in that it causes the required tractive force to fall to a value lower than a value determined on the basis of the operation amount of the accelerator operating member when the engine rotation speed is increased in response to an increase in the operation amount of the work implement operating member . an engine ; a hydraulic pump driven by the engine ; a work implement driven by hydraulic fluid discharged from the hydraulic pump ; a travel device driven by the engine ; an accelerator operating member for changing an engine rotation speed; a work implement operating member for operating the work implement ; a control unit for causing a speed of the work implement to increase by causing the engine rotation speed to increase when an operation amount of the work implement operating member is increased; and a power transmission device that has an input shaft , an output shaft , and a motor (MG1, MG2), the power transmission device transmitting driving power from the engine to the travel device ; wherein the power transmission device is configured so that a rotation speed ratio of the output shaft with respect to the input shaft is changed by changing a rotation speed of the motor (MG1, MG2), the control unit controls a tractive force of the vehicle by controlling an output torque of the motor (MG1, MG2), the control unit determines a required tractive force which is a target tractive force of the travel device on the basis of the operation amount of the accelerator operating member and controls the output torque of the motor (MG1, MG2) so that the tractive force of the vehicle becomes the required tractive force, and the control unit is characterized in that it causes the required tractive force to fall to a value lower than a value determined on the basis of the operation amount of the accelerator operating member when the engine rotation speed is increased in response to an increase in the operation amount of the work implement operating member . <EOS>