The geochemistry survey analysis was conducted on the soil samples collected from the Yixing area in 2004, 2009, and 2015 years, and the results show that the pH-value of surface soil varies from 3.53 to 8.86. Specifically, the acidic soils and strongly acidic soil generally distribute in the distribution of hill sandstone strata. The weak alkaline soil generally distributethe in the distribution of limestone strata. In the alluvial lake plain area, most soil is weakly acidic. And it shows the soil parent material and topographic features impact soil PH-values. Comparing with the changes of the surface soil pH-values within the past six years, the result show that there are 49.77% soils with decreased pH-value, the 23.53% soil with increased pH-valua, and 26.70% soils with relative stable PH-value. Due to the impacts of industrialization development on the environment, the acid rain plays an important role in soil acidification. Affected by farming and among others, the pH-value of surface soil in the alluvial lake plain area are lower than those of deep layer soil by around 1.2. The acidification of the surface soil occurs mainly in the tillage layer, the depth is about 30cm, and the bottom soil is basically neutral. From the general point of view, the analytical results of surface soil in the Yixing area show a trend of acidification. Some necessary measures must be done to prevent further deterioration.