Jiangnan in the Western Han Dynasty was still in the stage of extensive farming, with backward production methods and low economic and cultural level. It was not until the Eastern Han Dynasty that the economy and culture of Jiangnan made progress. Later, the economy of Jiangnan developed further at a faster speed, surpassing the Central Plains. This situation is the result of the continuous development and evolution of history. At the end of the Eastern Han Dynasty, many heroes rose together, Zhongzhou was troubled, and the Central Plains was in frequent wars. People in the Central Plains live in dire straits and cannot engage in normal production and life. In order to seek a more stable place to live, there has been a large-scale wave of immigrants from the Central Plains to the south of the Yangtze River, which is called "avoiding chaos in the south of the Yangtze River" in history. This immigration brought the most advanced science and technology, agriculture and handicraft technology in the world, as well as a large number of labor and sufficient funds to the south, which provided the necessary conditions for the economic development of Jiangnan and laid a solid foundation for the rapid economic and cultural development of Jiangnan in the future. At the end of the Eastern Han Dynasty, the three countries were divided, the war in the north continued, and the south was relatively stable. The major wars of the Three Kingdoms, the Jin Dynasty and the Southern and Northern Dynasties all took place in the north, and basically did not spread to the south of the Yangtze River. For example, the famous battles of Guandu, Chibi and Mud Water all took place in the north, and there was no stable production environment at all. It is the stable environment in the south that ensures the economic development in the south. At the end of the Eastern Han Dynasty, the rulers began to develop water conservancy in the south of the Yangtze River. The magistrate of Huiji built a "mirror lake", built ponds to store water in Huiji and Yin Shan, and adjusted the water quantity at any time according to the flood and drought situation. Therefore, there were no famine years, with 3 10 miles of dikes and 3,000 hectares of irrigated fields. This is a large-scale water conservancy project. Then some rulers in the south of the Yangtze River also took measures to develop the economy. For example, during the Three Kingdoms period, Shu Han realized the policy of tax reduction and rewarding farming, and Jiangnan also reversed the backward production situation of engaging in agriculture with relatively primitive farming techniques. Emperor Wu of the Southern Dynasties paid more attention to developing production and reducing the burden on farmers. The development of water conservancy, the improvement of production technology and the support of rulers have created good conditions for the rapid development of Jiangnan economy. It can be said that Jiangnan ushered in unprecedented development after the Eastern Han Dynasty. It is a series of conditions that have contributed to the economic and cultural development of Jiangnan, and I think the above three points are the most important reasons. With the economic progress, the cultural outlook of Jiangnan has also taken on a new look. After such a historical process, the cultural gap between Jiangnan and the Central Plains began to narrow, and the civilization level of Jiangnan improved significantly, which prepared the conditions for the later transfer of the national economic and cultural center to the southeast. During the Three Kingdoms period, Wu Jiandu established his career, and the southern political center appeared, which promoted the development of the southern economy. After the war in Surabaya, the north and the south confronted each other, the south was relatively stable, and the east was south. Such as Emperor Wu of Song's rectification of politics and economy. (2) The uprisings of Sun Si and Lu Xun dealt a heavy blow to the southern foot soldiers landlords. Adjusted the land ownership relationship and class relationship of eight counties in southeast China. Some land was returned to the working people, and the status of some tenant farmers, "Le Shu", "handmaiden" and soldiers was improved or liberated. This has played an important role in the recovery and development of social economy. (3) During the decades before and after the establishment of the Eastern Jin Dynasty, millions of people from the Central Plains flocked to the south. Among the people from the north and south, there are many farmers. Whether they become the dependent population of the landlord's manor or the yeoman, they are the main labor force to develop the south. (4) With the southward migration of the population in the Central Plains, advanced production tools and technologies spread rapidly, and cattle sowing technology was widely promoted. Two cows were used to raise money, intensively cultivated, manure fields and iron tools were widely promoted and used, and the southern economy was developed.