Soil salinization is a major environmental risk caused by natural or human activities, and it has an important adverse effect on the industrial and agricultural production activities of mankind. The authors conducted the study of the layout of the 6 representative soil salinization profiles in the coastal areas of Tianjin, and chose 4 profiles as the monitoring sections for the two-year monthly sampling and monitoring. Studies show that the soil salinity profiles are of the bottom accumulation types in coastal area, except for BHY6 soil profile which shows the balance of soil profile type with years of farming. The cations are mainly Na⁺, and the anions are mainly Cl^- or Cl^- and HCO₃^-. From the lower soil profile to the bottom of the shallow groundwater level, the proportions of Na⁺, Cl^- ions in soil possess the absolute superiority in the shallow groundwater with significantly higher salinity (up to saline degree), and this shows the basic characteristics of coastal solonchak. Climatic factors, salinity and depth of the shallow groundwater and the vegetation in surface soil are important factors affecting soil salinization of coastal areas. The surface soil shows the features of salt accumulation in spring, desalination in summer, and slow salt accumulation in autumn and winter. The shallow groundwater mineralization degree is higher, and the shallower the buried depth, the higher the soil salt content. The fruit trees and long cultivated land can reduce soil salt accumulation effectively and lower the degree of soil salinization of soil in coastal areas, which is crucial for the protection and improvement of soil.