In Shimao Site, stone city walls, city gates, watchtowers, comer towers and auxiliary structures similar to-bastions are found. The city site comprised the "Imperial City Terrace'', the inner city and the outer city, the general area of which would be larger than 400ha. The eastern gatc of the outer city consisting of the inner and outer barbicans, stone-lined rammed earth gate body, the guardhouses, and so on had huge scale, complex structure and advanced construction technique, and yielded jade spades, jade huang-semicircular pendant, murals, stone sculptures and potteries and other important artifacts of the late Longshan Age to the Xia Dynasty. Shimao Site is the largest city site of the Longshan Age to the Xia Dynasty known to date, which provided brand-new materials for the research on the origin of Chinese Civilization and is very meaningful for understanding the pattern of the early civilizations in China under the framework of "ancient culture, ancient city and ancient state".