China was an agricultural economy in ancient times. Basically, when there is a large population, the economy will be developed, so the southward migration of population is also the process of the economic center of gravity moving southward. At the end of the Eastern Han Dynasty, Sun Quan of the State of Wu developed Southeast Yi in the Three Kingdoms period, which went through the Five Chaos, the Eastern and Western Jin and Southern Dynasties, the Sui and Tang Dynasties, the Five Dynasties and Ten Kingdoms, and was completed in the Southern Song Dynasty. So far, the economy and population in southern China have surpassed those in the north. In this process, there were three climaxes of population migration to the south, all because of three major wars in the north.

The first time was the Eight Kings Rebellion at the end of the Western Jin Dynasty-Yongjia Rebellion.

Civil strife and foreign invasion occurred in the Western Jin Dynasty in 3 10. The rebellion of the Eight Kings in the Western Jin Dynasty was a civil strife in which brothers of the same clan fought for rights. Yongjia five years, 3 1 1 year, Liu Yuan's son led the troops to formally capture Luoyang and destroy the Western Jin regime. At this point, the turmoil that lasted for 16 years began, with five chaos and feuds between ethnic groups.

More than one million people from the Central Plains crossed Huainan for more than 200 years, which was the first climax of China's ancient population migration to the south.

The second time was the Anshi Rebellion (Tianbao Rebellion) during the Tianbao period of Emperor Xuanzong of the Tang Dynasty.

The Anshi Rebellion was a civil war waged by Tang generals An Lushan and Shi Siming from the last years of Xuanzong of the Tang Dynasty to the early years of Daizong of China (February 755 16 to February 763 17), which was a turning point in the rise and fall of the Tang Dynasty and also caused the separatist regime of the Tang Dynasty. Because An Lushan and Shi Siming were the main initiators of the anti-Tang Dynasty, the story was named An Shi. Because it broke out in Tianbao period of Xuanzong in Tang Dynasty, it was also called Tianbao Rebellion. At this time, there was a second climax of population migration to the south in China, which was called "the four seas are like Yongjia flowing south" in history, and then "the world plans to raise the southeast".

In Henan, Shandong and Hubei, many areas in Fiona Fang are sparsely populated, and even the suburb of Luoyang, which is "the city is broken and the households are not satisfied with the white", is "bowing to the wild hazelnut" (History of the New Five Dynasties).

The third time, the difficulty of Jingkang in Song Dynasty.

After the development of five dynasties and ten countries, paddy field agriculture in the south has surpassed dry land agriculture in the north. At the end of the Northern Song Dynasty, on November 26th of the first year of Jingkang, Jin Jun captured the capital Bianliang and captured Huidi and Qin.

In May of the second year of Jingkang, Song Gaozong and Zhao Gou acceded to the throne in Nanjing (now Shangqiu, Henan Province). Most officials were distracted and their families moved south. Since then, Emperor Gaozong first moved the capital to Yangzhou, but he couldn't escape all the way, and his capital was Lin 'an (now Hangzhou). With the collapse of half the country in the Song Dynasty, the wave of people moving south is getting higher and higher.

In the early Southern Song Dynasty, the southeast region with Zhejiang as the center accepted the most northern immigrants. The establishment of Hangzhou's status immediately attracted a large number of immigrants. Compared with the previous great migration, the migration area of immigrants in Jingkang Du Nan period has been greatly expanded, and Lingnan area, known as "wet", has become a refuge for literati. "When Emperor Gaozong crossed the south, people would return to the city." History called "Jingkang Du Nan".