A vehicle trunk floor cover position fixing member that enables the cover, which can be opened and closed over an additional space by means of a rotational movement around the place where it is connected to the trunk floor, to remain in open position in order for the additional space provided under the vehicle trunk floor to be used, comprising - at least one mounting hole which is provided in the form of a hole on the trunk side wall that is perpendicular to the wtrunk floor, - at least one body which is a hollow structure disposed on the outer surface of the trunk side wall so as to correspond to the mounting hole, - at least one guideway, which is provided on the body so as to correspond to the mounting hole, and which is in the form of a hollow circular channel, - at least one headpiece, which fits into the mounting hole upon contact of the cover during opening of the cover by the user's power, and which, in case of the closing movement of the cover, abuts the cover thereby enabling the cover to remain in open position, - at least one shaft, which extends from the headpiece into the guideway provided on the body, and which enables the headpiece to move forward and backward only in horizontal axis when a force acts on the headpiece, - at least one elastic member, which is positioned so as to surround the outer surface of the shaft and the guideway and is compressed between the headpiece and the body when a force acts on the headpiece, and which pushes the headpiece towards the trunk space upon cancellation of the force acting on the headpiece, characterized in that - at least one skirt, which is provided in the form of a protrusion at the part of the headpiece that contacts the outer surface of the trunk side coating, and which restricts movement of the headpiece out towards the trunk space over the mounting hole. - at least one mounting hole which is provided in the form of a hole on the trunk side wall that is perpendicular to the wtrunk floor, - at least one body which is a hollow structure disposed on the outer surface of the trunk side wall so as to correspond to the mounting hole, - at least one guideway, which is provided on the body so as to correspond to the mounting hole, and which is in the form of a hollow circular channel, - at least one headpiece, which fits into the mounting hole upon contact of the cover during opening of the cover by the user's power, and which, in case of the closing movement of the cover, abuts the cover thereby enabling the cover to remain in open position, - at least one shaft, which extends from the headpiece into the guideway provided on the body, and which enables the headpiece to move forward and backward only in horizontal axis when a force acts on the headpiece, - at least one elastic member, which is positioned so as to surround the outer surface of the shaft and the guideway and is compressed between the headpiece and the body when a force acts on the headpiece, and which pushes the headpiece towards the trunk space upon cancellation of the force acting on the headpiece, characterized in that - at least one skirt, which is provided in the form of a protrusion at the part of the headpiece that contacts the outer surface of the trunk side coating, and which restricts movement of the headpiece out towards the trunk space over the mounting hole.