Abstract: Xinjiang is located at the remote northwest China inland regions where the weather is dry and lack of rainfall, and it experiences serious evaporation loss. For the regions like this, it is urgent to reduce unnecessary loss of water resources, and to this end, we carried out a special experimental study. The purpose of the experiment is to reduce water-surface evaporation and to conserve water resources. We selected polar floating ball as anti-evaporation material, and explored the influences of different coverage areas and enclosure structures on suppression rate of evaporation. We divided the floating balls into two groups and placed them near the reservoir for better observation and management, and then set up five different coverage areas ( i.e. 0.28, 0.43, 0.60, 0.79, 1.02 m2) for each group (coverage areas exclude white enclosure structure). We then recorded humidity area under different wind speed, and calculated the suppression rate of evaporation of the floating balls. The results showed that the suppression rate of evaporation is related to the coverage area and the enclosure structure. When applying triangle enclosure with coverage area of 1.02 m2, the suppression rate of evaporation is 83.8%, which reaches its optimal rate. As the coverage area increases, suppression rate of evaporation gradually increases. When the suppression rate approaches 91%, considering the stability of the structure, a 4.48 m2 triangular enclosure structure should be used as a covering unit for partial placement.