The invention discloses an improvement of a clamping structure of a tool box. A common hand tool display box is under a flatly unfolded state when opened, and is not beneficial for being displayed and inconvenient for users to look for needed tools. In order to improve the problems, the clamping structure among a box body, a handle and a box cover of the tool box is specially improved so that the handle of the tool box can be freely rotated relative to the box body. Therefore, the box body can be supported at an inclination angle through the handle, and the users can have a clear view of hand tools in the box body and conveniently look for the hand tools.