Only a few wooden structures in the Mogao caves have survived until today, which makes research on such objects of particular significance. The earliest artifact is a wooden bracket of the Northern Wei dynasty, while a low and narrow wooden doorframe is the only one of the Northern Zhou dynasty relics accompanied by any historical information, the contents of which have provided valuable evidence for research on the development of ancient architecture. For example, the plane, a common tool for smoothing wood, had not been invented yet, and the various components of the doorframe found at Mogao correspond most closely to blueprints laid out in the text Construction Methods compiled in the Song dynasty. This indicates that ancient Chinese architecture developed very slowly, and that this might be the only wooden doorframe of the Northern Zhou dynasty remaining today.
