<p>Until the 1950s, Schistosomiasis was prevalent for more than 150 years in She County of Anhui Province, with three general disease trends. First, starting from a base of limited and scattered cases of Schistosomiasis before the middle Qing dynasty, the disease expanded rapidly from the middle to the late Qing (1736–1912), and subsequently reached pandemic proportions by the mid-20th century. Second, Schistosomiasis spread from the low-lying areas to higher terrain. Third, the disease spread mainly from downstream to upstream in each of the four main rivers that flow through the county. Although present in Huizhou Prefecture since the Ming and early Qing Dynasties, over these 150 years, the most virulent area of Schistosomiasis was in She County, its core region. There was an intimate connection between water control efforts, agricultural productivity, and Schistosomiasis prevalence in She County. From the perspective of disease history, this region became the area of an “evil plague” in the middle of Qing Dynasty, causing loss of population, a decline in labor supply, and a consequent and significant in-migration.</p>