Abstract: The cotton field irrigation experiments were carried out to study the effects of two irrigation methods(alternate partial root-zone drip irrigation under mulch (APRD) and conventional root-zone drip irrigation under mulch (CRD)) and three water application rates(3750, 4500, 5250 m3/hm2) on the soil water consumption, the characteristics of cotton growth(such as cotton stem height, root length, and so on), and water use efficiency (WUE) of cotton. Results in cotton field of arid area showed that the maximum vertical soil wetted depth was more than 50 cm and the maximum horizontal soil wetted radius was 40 cm under moderate irrigation level(4500 m3/hm2) of APRD, and the order of soil water content was the middle sites of mulch＞the edge sites of much＞the middle sites of bare land. Average soil water content had increasing trend during the whole growing stage of cotton, stem height and root length of cotton were increased with the water application rate. The effects of different irrigation methods on the cotton stem height and root length were not significantly under the same water application rates, and the effects of the water application rates on the cotton stem height and root length under APRD were larger than those under CRD. Compare with CRD, APRD constrains transpiration rate of cotton, which was beneficial to the improvement of water use efficiency by reducing soil evaporation and water consumption of crop transpiration. There was an important role to obtain high yield and high water use efficiency in the drip irrigation cotton field of arid area.