Abstract: In order to study the effect of cotton planting on soil physical characteristics and water-salt dynamic of coastal clay solonchak, field experiments were conducted in Yellow River Delta coastal clay salinization moisture soil area. Two treatments: three years continuous cotton planting and salty land, were set up, the effect of cotton planting on soil bulk density, saturated hydraulic conductivity and water-salt dynamic under different conditions were studied. The results showed that compared with salty land, cotton planting treatment decreased the soil bulk density in 0-20 cm soil layer by 15% (P<0.01) and increased the saturated hydraulic conductivity by 89.23% (P<0.05). Under the condition of evaporation in spring, the soil salt content of 0-20, 20-40, 40-60, 60-80 and 80-100 cm soil layer in cotton planting treatment decreased by 52.07%, 55.17%, 55.23%, 53.78% and 47.43%, respectively, in comparing with that of salty land. In addition, cotton planting could increase the soil salt leaching by small amount of rainfall, restrain salt accumulation in topsoil effectively, make the salinity in soil tillage layer lower than 3 g/kg during cotton growth period, and ensure cotton normal growth in different stages, thus it was one of the effective ways to improve and utilize salty land.