Abstract: Gravel-sand mulching is an effective agricultural measure to restrain soil water evaporation in arid and semiarid area. Watermelon as the main crop was planted on gravel-sand mulched field in Ningxia due to high quality of fruits. However, scarcity of rainfall and deficiency of fresh water resource were the limiting factors for the development and production of watermelon. More and more farmers irrigated watermelon with ground brackish water to increase and maintain fruit yield in recent years. Therefore, understanding the distribution and transportation of water and salt under gravel-sand mulch with brackish water irrigation played an important role to rationally use brackish water. A soil-column experiment was carried out to investigate the effects of gravel-sand mulching on the distribution and movement of soil water and salts with different amounts of brackish water irrigation under the condition of simulated evaporation with an incandescent lamp as heat source. Six treatments were set in this experiment including 3 irrigation water levels with and without gravel-sand mulching. Irrigation water amount was based on planned irrigation depth and difference of air dried soil moisture between field capacity. The planning depths of low, medium and high irrigation amount treatments were 40, 60 and 80 cm respectively and the salinity of brackish water was 2 g/L, similar with local ground water. Results showed that, compared with non-mulched treatment, gravel-sand mulching increased the infiltration depth, the maximum increasing range of depth being up to 8 cm, and reduced the accumulative evaporation of soil water by 74%, 54% and 21% with low, medium and high irrigation amount respectively during the experimental period of 15 days, and the reduction of accumulative evaporation was declined with the increase of irrigation amount. Moreover, there was an evident division point in the soil profile during the process of soil water redistribution, whose soil water contents increased by 2%-5% with gravel-sand mulches as compared with no mulches. Soil water content decreased above the point and increased below it. The decreasing ranges of soil water in the upper soil layer were narrowed with gravel-sand mulching compared to no mulches. For example, it was merely 16.9% with gravel-sand mulches while 34% with no mulches in low irrigation amount. At the same time, the accumulation of soil salt in the top surface soil was evidently restrained by 92.4%-95.2% with gravel-sand mulches while the peak value of soil salt content of soil profile increased by 11.02%-37.55%. The locations of salt content peaks in the soil profiles were moving downward with the prolonging of experimental time in gravel-sand mulching treatment and were deeper than those of without mulching. The salt peak location with gravel-sand mulched treatment was 10 cm deeper than that of without mulching at the end of experiment. It indicates that gravel-sand mulching restrains salt accumulation in the top surface soil and drives soil salt to move to deeper soil layer through reducing the evaporation of the upper soil water and increasing soil water infiltration and soil water content of deep soil layer under the condition of simulated evaporation and brackish water irrigation.