Soil samples were collected from afforested woodlots different in tree species for in-lab analysis of total salt content, anion and cation compositions, total alkalinity, pH, electrical conductivity, and alkalization degree, of which a systematic study was done. Results show: no CO₃²⁻ was detected in a tract of clearing as control and all the woodlots; afforestation significantly changed the content of soluble salts, like Na⁺, Cl⁻, SO₄²⁻ and HCO₃⁻ and reduced the content of total salt in the soils; in afforested soils, anions SO₄²⁻+ HCO₃⁻replaced SO₄²⁻+ Cl⁻ in dominancy; soil pH and alkalization degree and total alkalinity varied in a similar trend; and among the woodlots, the one of Amorpha fruticosa was the highest in alkalization degree, and followed by Woodlot Tamarix chinensis; Correlation analysis indicates that soil total salt content (y) is in extremely significant positive linear relationship with electrical conductivity (x), so it is feasible to calculate total salt content with soil electrical conductivity in grading the area by salinization degree. The findings of the study may serve as reference in elucidating salinization-alkalization processes of the coastal saline soil and in ameliorating the soil in the Yellow River Delta.