There are currently two prevailing interpretations on the process of construction of Mogao Cave285 in Dunhuang dated to the Western Wei period. One is that all sculptures and paintings in the cave were produced under a consistent plan and that the sculptures and paintings on each wall represent interrelated subjects. The other is that decorations of the cave were first made on the west wall, next on the south wall and ceiling, and lastly on the north and east walls, and that some change was made in the original plan to introduce new ideas and painting styles from the Central Plains. Supporting the latter interpretation, the author of this article thoroughly examines the paintings on the north wall, including the styles, techniques, materials, way of applying pigments, composition of donors, clothing, and Chinese inscriptions added to the images, and considers that the seven preaching scenes painted on the north wall were completed by four different groups of painters.The author further observes that the seven preaching scenes could be small-sized donations offered by some various families of Chinese and non-Chinese Hu and regards Cave 285 as one of the early cases in which the Mogao Caves- hitherto a place reserved exclusively for monks’ practices- were opened to lay believers.