Abstract: A cylinder control device of a hydraulic cylinder apparatus including a two-position, directional control valve having a pilot chamber for effecting control of reversal of the direction of movement of a piston, and a control valve movable between two positions depending on the pressure of working fluid in a conduit on the pump side. The control valve is mounted in a passage connecting the pilot chamber of the two-position, directional control valve to a valve means capable of bringing the pilot chamber into communication with conduit on the fluid discharging tank side when the cylinder piston reaches a predetermined position in its rearward stroke. Alternatively, the control valve may be mounted in a passage connecting the pilot chamber of the two-position, directional control valve to another valve means capable of bringing the pilot chamber into communication with the conduit on the pump side when the cylinder piston reaches the end of its forward stroke.