PURPOSE: To improve a steering force characteristic, by selectively using throttled parts in a rotary type valve for high and low speed use while automatically selecting use of the throttled parts to increase a level of adjustment of steering force in proportion to a car speed.

CONSTITUTION: A pump port 7, tank port 8 and left and right supply ports 9, 10 to a power cylinder formed to a valve housing 6 are connected through a pressurized oil introducing port 12, return port 13 and output port 14 to throttled parts 11 plurally formed in the peripheral direction between a rotor 4 and valve sleeve 5. The above throttled parts 11 are divided into throttled parts 11A for high speed use, formed by two neighboring ones of the throttled parts and two neighboring ones located in a symmetrical position of the shaft with respect to the former two neighboring ones, and throttled parts 11B for low speed use formed by the others. Then the sleeve 5 can be slided in the axial direction in accordance with a difference between back pressures applied to both end faces 5A, 5B of the sleeve 5 correspondingly to a speed, and the parts 11A, 11B are selectively used by this sliding action.