Aiming to characterize soil salinization, soil salinity profile types and distribution in the low plain around the Bohai Sea, soil samples were analyzed. The results showed that the variations of soil salinity in the surface layer belonged to highly variation degree, soil salinity in other layers belonged to moderate variation degree in horizontal direction, while in the vertical direction, their differences are small. Soil salinity could be influenced by 5 principle components which were soil salinization, soil alkalization, total regional dissolved soild, groundwater level, source of kalium, and the cumulative contribution of these principle components added up to 87.88%.