The dynamic changes of saline soil evaporation,water content and salinity in response to straw mulching were investigated. T he results showed that,(1) soil evaporation decreased with the increase of straw mulching,however,the reduction efficiency of the straw mulching remained steady when straw mulching quantity was over 7500 kg/hm²;( 2) evaporation inhibition rate were 80.54%,79.01%,62.45 %,and 37.93%, with straw mulching of 10500 kg/hm², 7500kg/ hm², 4500 kg/hm², and 1500 kg/hm²,respectively;(3)the watercontents of soil layers increased with the amounts of straw mulching. When straw mulching was 7500 kg/hm², the water content reached its maximum and the salinity approached its lowest level in the soil layer of 0-10 cm, with an increase of 9. 28% and a reduction of 3. 21% comparing to the control, respectively. Therefore, straw mulching on saline soils can potentially reduce water loss through evaporation, enhance water use efficiency, inhibit surface salt accumulation, and then significantly improve soil quality of saline soils.