Abstract: A large amount of geochemistry data has been obtained through the Land Quality Geochemistry Assessment Project in Honghu City, Hubei Province. Based on the overall study on the project data acquired over the past four years, the soil acidity and alkalinity of agricultural land in each town is analyzed systematically. The results show that the soil acidity and alkalinity in the southern and northern towns are higher than those in the middle towns. The trend analysis shows that the soil pH values increases gradually from west to east but does not change obviously from north to south. The influence on soil pH values from different types of soil is descending in following order: sandy soil type fluvo-aquic soil> sandy soil type calcareous fluvo-aquic soil> light-colored meadow soil=loamy calcareous fluvo-aquic soil> calcareous soil field> clay calcareous fluvo-aquic soil> shallow calcareous fluvo-aquic soil> calcareous cyan muddy field> loamy fluvo-aquic soil> muddy field> cyan muddy field> clay fluvo-aquic soil> shallow fluvo-aquic soil filed> yellow brown soil. In addition, the pH values of different parent materials are in descending order as follows:alluvial sediments> lake sediments> Quaternary clay sediments> river sediments> red sandstone weathering materials. The average pH value of soil in Honghu decreases by 0.87 units from 1982 to 2007, increases by 0.35 units from 2007 to 2014, and increases by 0.47 units from 2014 to 2019. The research results can provide decision-making reference for the local government to protect the quality of cultivated land, control the acidification of cultivated land and adjust the structure of agricultural industry.