[Variolation, pioneer of modern immunology].

Smallpox spread into China at the end of the Han Dynasty. Therapeutic remedies were first recorded in Ge Hong's Zhou Hou Jiu Zu Fang in the Jin Dynasty. It is possible that variolation made its first appearance in the Northern Song Dynasty. It can be sure that there was a variolation centre in Taiping County of Ningguo District in Anhui. The Kangxi Emperor of the Qing Dynasty advocated and encouraged the popularization of the art which was then spread outside China. Edward Jenner, the English physician who practised variolation, modified variolation into vaccination, which eventually lead to the formation of modern immunology and the declaration of eradication of smallpox on the Earth by WHO in 1980. The article describes the historical process of variolation to vaccination and points out that the modified variolation was safe and reliable. Unfortunately, the westerners only followed the simple smallpox-juice method which was relatively more dangerous.