Pine wilt disease was first discovered in People’s Republic of China in 1982 in Nanjing City, Jiangsu Province (Cheng et al. 1986). That year only 256 dead trees were found in the city. Subsequently, the disease has spread to 10 provinces and a city: Jiangsu, Zhejiang, Anhui, Guangdong, Shandong, Jiangxi, Hubei, Hunan, Yunnan, Guizhou Provinces and Chongqing City (Fig. I.7). The affected areas have reached nearly 80,000 ha and 50,000,000 trees have been killed by the disease. In recent years, the disease has spread quickly. The infected forest areas and the number of dead trees per year since 1982 are shown in Figs. I.8 and I.9. The disease threatens Huangshang and many other famous scenic spots and places of World Natural or Cultural Heritages; or both, and so, the disease has become a serious forest problem affecting local economies.