It refers to the ancient road network for tea-horse trade in the frontier area of Southwest China. It rose up in the Tang and Song dynasties (618 – 1279), flourished in the Ming and Qing dynasties (1368 – 1912), and peaked in the middle and late period of World War II. It is a non-governmental international trade channel with caravan as the main means of transportation, a corridor not only for economic and cultural exchanges among ethnic groups in Southwest China, but also connecting Central Asia, Southeast Asia, South Asia, and West Asia, as far as Europe, exerting far-reaching influences in social, economic and cultural exchanges up to now. In 2011, it was listed as a national key cultural relics protection site, which marked the beginning of protection and utilization.