Baodai Bridge，also known as "Long Bridge", is located at the bank of Grand Canal of China in Wuzhong District of Suzhou City, Jiangsu Province. It is one of the "Ten Famous Bridges in China" together with Anji Bridge in Zhaozhou, Lugouqiao Bridge in Beijing and other renowned bridges.

The Baodai Bridge (Precious Belt Bridge) was built by Wang Zhongshu, a magistrate of Suzhou prefecture during the time of the Yuanhe Emperor of the Tang Dynasty (805-820). To raise money to finance the bridgework, Wang used his expensive belt, hence the name.

Baodai Bridge is the longest multi-hole stone bridge among the existing ancient bridges in China. Having a history of up to a thousand years, Baodai Bridge was originally built in the Tang Dynasty（618-907）and was rebuilt by later generations for many times. The bridge was refurbished during the reign of the Zhengtong emperor of the Ming Dynasty, but was seriously damaged by the British incursion during the reign of the Xianfeng emperor of the Qing, and by the Japanese, during their invasion (1937-1945). In 1956, it was repaired to obtain its original appearance.

The 317-meter length and width as 4.1 meters width bridge with 53 arches was made out of stone from Jinshan Mountain. Both ends of the bridge are of trump-shape and respectively fitted with a pair of martial bluestone lions. On the northern side of the bridge stand a stone-tablet pavilion and a stone pagoda. The stone pagoda is 4 meters in height and is made by carving the entire block of bluestone, with the square pedestal being carved with wave and dragon veins.

Voussoirs on the bridge are connected by blocks with rabbets and mortises, which contributes to the magnificence of the whole bridge. Spans of the holes are approximately 3.9 meters. The tri-arc hole in the middle is especially expansive and allows for ship passage, while other ones on both sides decline gradually and form camber lines. The bridge is not fitted with side boards for the convenience of foot passengers and boat trackers.

Piers of Baodai Bridge are peculiarly designed to be such that peg stakes are mounted under the bridge; ground stones are placed on top of the peg stakes; and bridge body is positioned on the ground stones. In addition, the lower end of the arch ring is embedded in the preset groove in the pier, which is hereby of "Flexible Pier". In contrast, the pier No.27 (counting from the northern end of the bridge) was converted into two consistent piers which are comparatively firm and of "Rigid Pier". Simultaneous utilization of two forms of piers has contributed not only to long-lasting preservation of the bridge, but also to its elegance and legerity.

Baodai Bridge is featured by complicated overall conformation, light structure and spectacular style，which is rare in the history of Chinese and foreign bridge. Its delicate design and beautiful surroundings make it appear just like a precious belt hovering over the river town. It was hereby listed as a famous attractive spot in the south of the lower reaches of Yangtze River and one of the historical and cultural relics under state protection.