This study analyzed the inorganic sulfur (SSO4) and total sulfur (ST) content as well as the isotopic signatures (delta34SSO4 and 834ST) in leaves of Pinus massoniana lamb. collected from Guizhou and Yunnan areas. The results indicated that the SSO4 and ST content in leaves at Guiyang areas was significantly higher than that at Yunnan areas, and the content of inorganic sulfur in the leaves was found to be directly related to the concentration of ambient sulfur dioxide, but no correlation was seen between the ST content and the ambient sulfur dioxide, showing the SSO4 content in leaves was more reliable to reflect the ambient sulfur input. The average value of delta34SSO4 in leaves at Guiyang areas ( -7. 22%o) was significantly lower than that at Yunnan areas(3. 85 per thousand) , which was related to the fact that the sulfur isotopic composition of coal at Guiyang areas is lower than that at Yunnan areas. The SSO4 and ST content in leaves around Kunming steel and Qujing power plant was inversely proportional to the distance from the factories, while around Kunming steel plant the value of 83SSO4 in leaves became more negative when the distance became larger while around Qujing power plant the value of 834Sso4 became more positive when the distance became larger, indicating that the SSO4 content and delta34SSO4, in leaves around Kunming steel and Qujing power plant were controlled by coal sources of atmospheric sulfur deposition.