This bridge once linked Gwancheol-dong and Janggyo-dong, and had placed on Cheonggyecheon between 51 Janggyo-dong and 11 Gwancheol-dong. Since there was a village called 'Jangchagol' near this bridge, it was appropriately named 'Jangchagol-dari' in the local region. However, its formal name was 'Jangtonggyo,' shortened to 'Janggyo.' This name originated from the 'Jangtongbang' in the Joseon Dynasty.

It was called 'Jangchanggyo' because there were long (Jang) warehouses (Chang) nearby. Judging from the eight characters of 'Sinmigaejo (repaired at Sinmi (the 8th year of the sexagenary)), and 'Gihaegaejo' (repaired at Gihae (the 36th year of the sexagenary)) inscribed on the western bridge post, is it thought that this bridge has been repaired twice. It joins the main stream of Cheonggyecheon with water from the Changdongcheon, and a stream flows through Hoehyeon-dong at Sogwangtonggyo (bridge).
The western section across Jangtonggyo therefore, forms a wide geographical feature of a river delta. This region became a destination for merchants as the commercial center of castle town in its early years, as well as the headquarters for Gyeongjuin (position) - a liaison man between the central government and the provincial government. Moreover, Yoo Daechi, a pioneer who displayed active measures of enlightenment in the 19th century Jungin (middle class in the Joseon Dynasty), lived in Jangtongbang, behind the present Bosingak (Belfry).