Abstract: Background Soil salinization is one of the major features of the ecological environment in the Yellow River Delta, and groundwater is the main water resource for plant growth and development in this saline soil. This study aims to provide scientific basis for the rational utilization of saline soil in the muddy coast, and management of planting protection forest for soil and water conservation. Methods In order to investigate the response of the distribution characteristics of soil moisture and salinity under different groundwater salinity, the soil columns with planting 3-year Tamarix chinensis Lour were selected as experimental material, and soil columns without planting as control (CK). The parameters of soil moisture and salinity, such as soil water content, soil salt content and absolute concentration of soil solution, were measured and analyzed under simulating groundwater levels of 1.8 m with 4 groundwater salinity gradients of fresh water (0 g/ L), brackish water (3 g/ L), saline water (8 g/ L) and salt water (20 g/ L), respectively. Results The groundwater salinity significantly affected the parameters of soil moisture and salinity under different soil profiles. With the increase of groundwater salinity, the content of soil moisture and salinity in the whole soil columns increased, while the absolute concentration of soil solution decreased. Compared with CK, the mean relative water contents in soil columns with planting T. chinensis at fresh water, brackish water, saline water and salt water decreased by 24.4%, 20.6%, 11.3% and 4.7%, respectively, and the mean soil salt contents of brackish water, saline water and salt water decreased by 6.7%, 5.6% and 8.7%, respectively. With the increase of soil depth under different groundwater salinity, the soil moisture rose, and the absolute concentration of soil solution decreased, while soil salinity decreased firstly and then increased, and reached the minimum value at the soil depth of 80 cm. Conclusions With the increase of groundwater mineralization, the content of soil moisture and salinity rose rapidly, especially at the top soil, indicating that planting T. chinensis significantly decreased the water content, salt content and absolute concentration of soil solution in soil columns. However, the effect of planting T. chinensis for decreasing soil moisture weakened with groundwater mineralization increasing, while that on salt inhibition enhanced.