Abstract: An improved magazine structure for nailing machines includes a magazine body. The magazine body includes a base disk, a supporting disk, and a rod fixedly disposed on the supporting disk. The base disk is provided with a slot for passage of the rod. The rod has a sliding wheel disposed at a bottom portion thereof to allow the rod to displace slidably along the slot. The rod is disposed at a central position of the base disk, whereby the rod disposed at the central position of the base disk is caused to displace slidably outward to bring the support disk to displace therewith, so that a nail reel can be fitted vertically onto the supporting disk to achieve convenient and quick installation of the nail reel.