Juyanhai is the second largest inland river in China, the Heihe tailing lake. [1] Han time called Yanze, Tang time called Yanhai, originating from the deep Heihe in Qilian Mountain, flowing through Qinghai, Gansu, Inner Mongolia three provinces more than 800 kilometers, into the Badan Jilin Desert northwest margin two Gobi depressions, forming two East and West lakes, the general name is Yanhai.