Abstract: Soil salinization is an important influence factor in the ecological protection and restoration of coastal areas. In order to understand soil salinization degree in Tianjin plain, soil samples outside the embankment were collected and investigated along three rivers from sea to land, including the Yongding New River, the Haihe River and the Duliujian River. The spatial gradient and variability of soil salinity in the sea-land direction were analyzed, by combining geostatistics with geographic information system (GIS) technology. The study potentially provided scientific basis for ecological protection and restoration, and land and sea coordination in Tianjin. The results showed that soil water-soluble salt content and soil alkalization appeared to be decreased gradually from the southeast to the northwest. Severe and above salinized soil was mainly distributed in Binhai New Area with 15 km from the coastline to the land. Solonchak and severe alkaline soil were primarily distributed in Dagang within 10 km to the sea, Tanggu and Hangu within 5 km from the coastline. Moderate saline soil was mainly distributed along the Duliujian River within 15-60 km from the coastline. Slight saline soil was mainly distributed along the mainstream of the Haihe River within 10-60 km from the coastline. The predominant cation in soil was mostly Na⁺, while the predominant anions transferred from Cl^- and ${\mathrm{SO}}_4^{2-}$ to ${\mathrm{SO}}_4^{2-}$ and ${\mathrm{CO}}_3^{2-}$ + ${\mathrm{HCO}}_3^{-}$ in the landward direction. Sulfate-chloride and chloride-sulfate soils were the primary saline soil types along the Duliujian River, sulfate-soda soil was the primary saline soil type along the central plain of the Haihe River, and sulfate-chloride and soda-sulfate soils were the primary saline soil types along the Yongding New River.