Abstract: An apparatus for controlling dynamic characteristics of an outer load includes a crank angle detecting device which detects a crank angle and an outer load detecting device which detects the outer load, output signals of the two detecting devices are input to a controlled hydraulic pressure correcting device in which an ideal value of outer load corresponding to the crank angle has been preset, a deflection rate between the detected outer load and the ideal value of outer load is judged in accordance with the detected crank angle and, each time that the deflection exceeds a predetermined range, the output of a hydraulic source for setting a balanced pressure is controlled so as to adjust the balanced pressure.