The ancient city of Luoyang existing down to the Han-Wei period was the royal or national capital of the Eastern Zhou, Eastern Han, Cao Wei, Western and Eastern Jin and Northern Wei periods. In 2001-2002, the Institute of Archaeology, Chinese Academy of Social Sciences, excavated the ruined main gate Changhemen of the Northern Wei palace-city on the Han-Wei Luoyang city-site. The work revealed all remains of the gate foundations, the left and right towers in front of the gate, the square between the towers, and parts of the courtyards on the western and eastern sides of the gate. The unique structure and layout of the gate towers display strong chronological features and special function with dignity above defense, which exerted great influence upon later buildings of this sort. The gate was constructed in the Cao Wei period. Its discovery has great value to inquiry into the form and location of the Luoyanggong Palace built in the early Cao Wei period as well as the location of the Han period North Palace in ancient Luoyang City.