yuchengquIntroduction：About Yucheng: Yucheng City, Ya'an City is a city area under the jurisdiction of Ya'an City, Sichuan Province, China. It is in the middle of the Sichuan Basin, the middle reaches of the Qingyi River, and the transition zone from the Chengdu Plain to the Qinghai-Tibet Plateau. 1060 square kilometers, 340,000 people in 2002.