Abstract: A structure of a door frame including four rails each formed with a first passage at one side, a second passage at an intermediate portion, a third passage at another side, a first slot at an edge, a second slot at a front side, a third slot at the front side, a fourth slot at another side, and a raised portion at a rear side, four right-angled connectors formed with a first shoulder at one side, a central block, and a second shoulder at another side adapted to be inserted into the first, second and third passages, four auxiliary locking members each fixedly installed into the third passage and having a slot for passage of electrical wires, four fastening posts each formed with a first groove at one side and a second groove at another side adapted to engage with the raised portion of the rails and right-angled connectors, and covering members arranged on the inner sides of the frame.