Abstract: In order to ascertain the effects of water-retaining agent on soil moisture characteristics under different soil moisture conditions after the growth of winter wheat, the effects of different dosage of water-retaining agent (T1：0；T2：27mg/kg；T3：54mg/kg；T4：81mg/kg) on soil water retention, supplying water and infiltration capacity were studied through potting experiment condition were studied. The results indicated that water-retaining agent increased the capability of soil water retention, supplying water, infiltration and available moisture. Under mild stress condition, the capability of soil water retention, infiltration and available moisture of treatment 3 were the best compared with other treatments, while treatment 4 was the best for the capability of supplying water compared with other treatments. Under sufficient irrigation, the capability of soil water retention, supplying water, infiltration and available moisture increased with the dosage of water-retaining agent, but there was not significant difference between treatment 3 and treatment 4. Compared with mild water stress, the capability of soil water retention, supplying water and infiltration under the condition of sufficient irrigation were higher. Soil available moisture of treatment 3 under mild water stress was highest among all treatments, which increased by 18.6% compared to the control. In all, from economical aspect, treatment 3 was the best to improve the soil properties.