Ecosystem sensitivity to acid deposition can be a basis for thederivation of cost-effective strategies to sulfur and nitrogenpollutant control, consequently is widely concerned around theworld. In the article, the relative sensitivity of terrestrialecosystem to acid deposition in South China is assessed andmapped using a new sensitivity classification system suitable tosubtropical ecosystem. The result shows that the distribution ofecosystem sensitivity to acid deposition in South China isalmost zonal, on the whole, sensitivity increases from the northand west to the south and east. The most sensitive areas are thenorthwest and southeast of Zhejiang province, the central partof Fujian province, and the northeast of Guangdong province andGuangxi Zhuang Autonomous Region, which are all in the old acidsoil areas with high precipitation and coniferous forests. Theresulting distribution of sensitive regions is different othermaps, including the sensitivity map which is implemented in theRAINS-Asia model.