Abstract: Small pox inoculation was introduced in western Zhejiang and southern Jiangsu provinces and gradually to eastern Zhejiang province early in the Qing Dynasty. Cowpox vaccination dates to the Daoguang reign but Cowpox Vaccination Bureaus were not established in most counties in Jiangnan until 1840. Different from small pox inoculation, cowpox vaccination spread quickly as the result of positive and rapid intervention from government officials once introduced. The establishment of the vaccination bureaus, however, was mainly the work of local communities. By the end of the Qing Dynasty, traces of small pox and cowpox could he found throughout the villages and towns of Jiangnan, but it is overly optimistic to estimate that more than thirty to forty percent of infants in Jiangnan had been vaccinated at the end of Qing Dynasty. Vaccination did play a role in population growth in Jiangnan during the Qing Dynasty, but its contribution, especially with regard to small pox, should not he over exaggerated.