Luoyang is the center and origin of ancient civilization in China. Heluo Plain was developed in agriculture and rich in water resources, which was the basis for controlling the traffic in the east, west, north and south at that time.
On the other hand, these two places have a very long history as capitals. The Western Zhou Dynasty was established in Haojing (near Chang 'an), and the Eastern Zhou Dynasty was established in Luoyang (the capital city before the Zhou Dynasty often changed on a small scale), which had a very good foundation for building a city.
After the establishment of the new dynasty, it is much easier to build the capital on the inherent basis than to relocate it, saving a lot of cost and time for reconstruction.
The Central Plains Dynasty no longer took Chang 'an Luoyang as its capital, but also after these two places were severely damaged, that is, after the Tang Dynasty, after the demise of the Tang Dynasty, wars continued, and Chang 'an and Luoyang, which were once prosperous and rich, basically declined.
Due to over-exploitation, the natural environment of Guanzhong and Heluo Plain was seriously damaged, and the feudal era could no longer bear the more rapidly growing population. Gradually abandoned.
At the same time, during the Yuan, Ming and Qing Dynasties, the territory of China increased, and Chang 'an, located in the west, was no longer suitable as the national capital. Due to the further excavation and dredging of the canal in Yuan Dynasty, Luoyang's geographical advantage is no longer obvious. In order to stabilize the political power, except Nanjing, which was established briefly in the early Ming Dynasty, the Yuan, Ming and Qing Dynasties all designated the capital as the capital with more obvious geographical advantages.