Longkou vermicelli is a specialty of Yantai City, Shandong Province and a national geographical indication agricultural product. In the late Ming and early Qing dynasties, Zhaoyuan people created a new skill of making mung bean vermicelli. Due to the geographical environment and climatic advantages, Zhaoyuan vermicelli is famous for its "uniform silk strips, flexible texture, smoothness and transparency". 1860, Zhaoyuan fans began to assemble and ship in Longkou Port. In order to distinguish it from other fans in Yantai, the words "Longkou fans" and "Zhaoyuan basic place" were marked on the package, which was originally called "Longkou fans".