A wheel loader comprising: a vehicle body frame; wheels (9, 10); a working device which is attached to the vehicle body frame and which has a lift arm capable of being rotated in an up/down direction; an engine which is attached to the vehicle body frame; an HST traveling device in which a variable displacement type HST pump driven by the engine and an HST motor driving the wheels (9, 10) are connected to each other in a closed circuit, and which has an HST pump control portion controlling input torque of the HST pump; a working machine pump which is driven by the engine to discharge pressure oil for operating the working device; a work mode selecting device which selects one from a power mode and an eco mode, the power mode serving as a work mode when the workload is a heavy load, the eco mode serving as a work mode when the workload is a light load; a detecting device which detects lifting operation of the lift arm of the working device; and a control device which controls input torque of the HST pump, characterized in that, the control device is adapted to control: the input torque of the HST pump in accordance with a preset eco mode characteristic by a command to the HST pump control portion when the eco mode is selected by the work mode selecting device; the input torque of the HST pump in accordance with a preset power mode characteristic by a command to the HST pump control portion when the power mode is selected by the work mode selecting device; and the input torque characteristic of the HST pump in accordance with a lifting operation characteristic in place of the eco mode characteristic when the lifting operation of the lift arm is detected by the detecting device after the eco mode has been selected, wherein the control device has a storage portion which stores an eco mode characteristic line, a power mode characteristic line, and a lifting operation characteristic line, wherein each of the eco mode characteristic line, the power mode characteristic line and the lifting operation characteristic line includes a characteristic line expressing a relation between engine speed and the input torque of the HST pump; and the lifting operation characteristic line is set as a characteristic in which a matching point as an intersection point of the lifting operation characteristic line with a working device operating engine torque characteristic line obtained by subtracting torque of the working machine pump from torque of the engine is provided between a matching point as an intersection point between the eco mode characteristic line and the working device operating engine torque characteristic line and a matching point as an intersection point between the power mode characteristic line and the working device operating engine torque characteristic line. a vehicle body frame; wheels (9, 10); a working device which is attached to the vehicle body frame and which has a lift arm capable of being rotated in an up/down direction; an engine which is attached to the vehicle body frame; an HST traveling device in which a variable displacement type HST pump driven by the engine and an HST motor driving the wheels (9, 10) are connected to each other in a closed circuit, and which has an HST pump control portion controlling input torque of the HST pump; a working machine pump which is driven by the engine to discharge pressure oil for operating the working device; a work mode selecting device which selects one from a power mode and an eco mode, the power mode serving as a work mode when the workload is a heavy load, the eco mode serving as a work mode when the workload is a light load; a detecting device which detects lifting operation of the lift arm of the working device; and a control device which controls input torque of the HST pump, the input torque of the HST pump in accordance with a preset eco mode characteristic by a command to the HST pump control portion when the eco mode is selected by the work mode selecting device; the input torque of the HST pump in accordance with a preset power mode characteristic by a command to the HST pump control portion when the power mode is selected by the work mode selecting device; and the input torque characteristic of the HST pump in accordance with a lifting operation characteristic in place of the eco mode characteristic when the lifting operation of the lift arm is detected by the detecting device after the eco mode has been selected, wherein the control device has a storage portion which stores an eco mode characteristic line, a power mode characteristic line, and a lifting operation characteristic line, wherein each of the eco mode characteristic line, the power mode characteristic line and the lifting operation characteristic line includes a characteristic line expressing a relation between engine speed and the input torque of the HST pump; and the lifting operation characteristic line is set as a characteristic in which a matching point as an intersection point of the lifting operation characteristic line with a working device operating engine torque characteristic line obtained by subtracting torque of the working machine pump from torque of the engine is provided between a matching point as an intersection point between the eco mode characteristic line and the working device operating engine torque characteristic line and a matching point as an intersection point between the power mode characteristic line and the working device operating engine torque characteristic line.