Tanshui occupied an important place in the transport network connecting Taiwan to Southeast Asia. Even before the arrival of Westerners in Taiwan, Han Chinese often crossed over from China to Tanshui, which is relatively close to the mainland. Here they engaged in barter trade with the Pingpu (meaning "plains") aborigines, with deer skins and sulphur being the most coveted products.
位於東南亞運輸要衝的淡水，早在洋人來台前，就因與大陸距離近，而常有漢人渡海來淡水，與住在附近的平埔族──凱達格蘭族以物易物換取商品，鹿皮、硫磺都是漢人眼中的搶手貨。