Abstract: The corrosion test of water and soil is an important content in geotechnical engineering investigation. It refers to the tests of local water and soil to determine the corrosiveness of the building foundation.《Standard for Survey of Geotechnical Engineering》(GB50021-2001):when the concrete structure is above the groundwater level, the corrosive test of soil sample should be taken; When the concrete structure is in ground water or surface water, the corrosive test of water should be taken; When part of the concrete structure is above the water table and part of the concrete structure is below the water table, the corrosive tests of soil samples and water samples should be taken; Only when there is sufficient experience and information to believe that the corrosivity of water and soil are negligible to the building foundation, no water and soil corrosion tests can be conducted. In order to improve the quality of engineering investigations and avoid serious consequences, This paper introduces the evaluation indexes of water and soil corrosion, the indexes include:PH value, Ca²⁺,Mg²⁺,Cl^-,CO₃^2-,HCO₃^-,OH^-,free CO₂,erosive CO₂,SO₄^2-,NH₄⁺,total mineralization and the experimental operation methods of the indexes, it summarizes the corrosive effect of each index on the building foundation, the factors that affect the data of each indicator, and the existence relationship between them.