The particle composition of the different soil layer,distribution characteristics of the soil moisture and the relevancy of the soil water in different soil layers were investigated in the field experiment.Results showed:(1) It was crucial reason that the particle composition of the soil layer decided the capability of the soil moisture retention,which reflected on the variety of the distribution and the movement actions of the soil water and affected the detention time in the soil.The percentage of the grit was higher in the soil layer,and the percentage of the clay content was lower,and the soil moisture was smaller.The detention time of the soil water in the loam was longer than in the sand soil.(2)The region of the soil moisture loss,the region of the soil moisture detention,and the region of the soil moisture transition were named for the soil layer from surface to 3 m depth in the field experiment district.The region of the soil moisture detention was the place of the soil water reserving,and provided the water resources for the plant.The influence of the particle content of the silty loam was great crucial for forming the region of the soil moisture detention and the capability of the soil moisture regulated.(3) With the deep under ground water table,irrigation water supplied the soil water and affected the redistribution characteristics of the soil moisture,which influenced the regulating capability of the region of the soil moisture detention and the growth of the crop and plant.