A side-locking sliding rail assembly for a drawer consisting of a fixed rail, a movable rail, an intermediate rail, a sliding device, a locating member, a hook block, an actuation member, at least one first compression spring, a second compression spring and an auto-opening mechanism carrier plate. The drawer can be temporarily secured in a position, subject to engagement of a pawl of a locating rod of the locating member with one of a series of sloping teeth along the auto-opening mechanism carrier plate, if the drawer is not accurately fully closed. Thereafter, the user can apply a pressure to push the drawer backward to the fully closed position avoiding rebound toward the open position. The arrangement of a second compression spring prevents tilting of the locating member, so that the locating rod will not be permitted to move forward when in the guide-in channel.