A hydraulic control system for a construction machine has a hydraulic actuator that drives an arm, a meter-out channel through which hydraulic fluid discharged from the hydraulic actuator flows, a variable restrictor provided in the meter-out channel, an operating device, and a controller that controls an opening area of the variable restrictor. A posture calculation unit calculates an angle made by the arm with respect to a horizontal direction, a meter-out opening area calculation unit calculates the opening area of the variable restrictor based on the angle made by the arm with respect to the horizontal direction and a time rate of change of the angle, and a meter-out control unit outputs a command signal to a solenoid valve used for adjusting the opening area of the variable restrictor, based on the opening area of the variable restrictor calculated by the meter-out opening area calculation unit.
