Wei Man was in Hansi County of North Korea.

After the destruction of Wei's Korea by Emperor Wu of the Han Dynasty, four counties, Le Lang, Lintun, Xuantu and Fan Zhen, were successively established in its jurisdiction, which was called "Han Four Counties" in history. There are many counties under the four counties, and the county governors are all Han Chinese sent by the Central Committee of the Han Dynasty. Obviously, the establishment of the "Four Counties of Han Dynasty" shows that Emperor Wu of Han Dynasty has brought the northern part of the Korean Peninsula under the rule of the Han Empire.

After Emperor Wu of the Han Dynasty, the county settings in the northern part of the Korean Peninsula changed. In the fifth year of Emperor Zhaodi (the first 82 years), he went to Lintun and Fan Zhen counties, and Le Lang and Xuantu counties. Lelang County's office is still in Pyongyang, North Korea, which rules the Yi and Wokuotai ethnic groups. Xuantu County Hall was originally rented by Fu Cha (now Xianxing, North Korea), and later moved to the northwest of Koguryo (now Xinbin area in eastern Liaoning) due to the invasion of the emperor, and governed the Koguryo, Fuyu and other ethnic groups.

The Han Dynasty ruled the northern counties of Korea, which objectively greatly promoted the economic and cultural exchanges between the Han Dynasty and the northern part of the Korean Peninsula and contributed to the spread of advanced culture of the Han Dynasty in the northern counties of Korea. At that time, not only Han officials went to work in four counties of North Korea, but also many wealthy businessmen and farmers went to do business and reclaim land. The four counties in North China are already a scene of Korean culture. This can also be proved by archaeological excavations. In recent years, in the archaeological excavations in four counties of Han Dynasty, a large number of official seals of Han Dynasty and vessels of various textures and shapes have been unearthed. Archaeologists call this cultural phenomenon "Le Lang culture", which is actually China culture. Among the archaeological discoveries of "Le Lang culture", the most representative is Le Lang's Tomb Group, which is located in the south of Tucheng, Le Lang District, Pyongyang, North Korea, with more than 2,000 tombs. Most of these mounds and mounds are square platforms, which are common shapes of tombs in China during the Zhou and Han Dynasties. There are mainly two kinds of tomb structures: wooden tombs and brick tombs, and their specific practices, styles and even subtle patterns on bricks are no different from those of Han tombs in the Central Plains of China. The funerary objects in the tomb are very rich, all of which are the cultural characteristics of China. Le Lang's Tomb can be regarded as a concrete testimony of the powerful influence of Han culture in North Korea. It is worth noting that the influence of this Han culture is not limited to the northern part of Korea where the "four Han counties" are located, but it is equally attractive and attractive to the southern part of the peninsula, which arouses their general yearning. As early as BC 109, that is, on the eve of Emperor Wu's invasion of Wei's Korea, the Mamu tribe in the south sent envoys to the Han Dynasty to make a pilgrimage to Emperor Wu, but it was not realized because of the obstruction of korean king Right Canal. After the establishment of the "Four Han Counties", the leaders of the southern tribes admired the Han culture in northern Le Lang, and many of them kept close contact with Lelang County in the Han Dynasty. Their exchanges with the North naturally promoted the exchanges and trade between the people of the North and the South. At the same time, northerners come from the south, which directly brings the advanced Le Lang culture in the north. For example, Ji Zhun Wang Nan, whose surname is North Korea, fled to Mahan area and claimed to be korean king, which naturally spread China culture indirectly. In the south, some tribes, even northerners, live with the indigenous people in the south, forming an immigrant society. From the unearthed cultural relics, it can be seen that the culture of Han Dynasty and Sijun at that time had influenced Jeju Island and other places at the southernmost tip of the peninsula.