in a hydraulic circuit system , when pressurized oil discharged from a single hydraulic pump is supplied to a plurality of actuators : the pressurized oil is supplied to heavily - loaded ones of the actuators at gradually reducing flow rates to reduce a shock , while supplied to lightly - loaded ones of the actuators at gradually increasing flow rates to increase working speeds of these lightly - loaded actuators . the hydraulic circuit system comprises a plurality of directional control valves one of which is provided with pressure - compensated flow control valves each of which is provided with a load lead - in passage having a restriction means . in addition , further comprised in the system are : relief valves for relieving the pressurized oil under the influence of load pressure of the actuators operated by the directional control valves ; a restriction orifice provided in a drain side of each of the relief valves so as to produce pressure therein .