Zhaozhou Bridge has another name called Anji Bridge and lies to the Xiao river of the south Zhao Country Hebei Province. It is the large famous ancient stone arch bridge which still exists in our country. It was built by Li Chun in the Sui period (A.D.590-608). The bridge which is form hole is 50.82 meters long and about 10 meters wide. The span of the bridge is 37.02 meters. The bridge arch is 7.23 meters high and is made up 28 stones side by side. The arch curve is gentle. There are four small arches on the bridge arc which is not only lose weight and save materials but also be easy to flow freshet and increase beauty. In the history of the bridge of the world it is the remarkable model in the design and craft. It also belongs to the invention because of the large span at that time reflects the intelligence and ability of the ancient working people of our country.