Abstract: A three-year experiment was conducted on the cotton growth and effect of decreasing soil salinity by using magnetization water for dripping irrigation under mulching plastic films. Results showed that magnetization water used in the experiment could reduce the soil salinity effectively, and promote the cotton growth and raise cotton yield and quality. At the 0-60 cm soil layer, magnetization water of dripping irrigation could decrease soil salinity rate about 20-30% purely. Simultaneously, the content of SO42- and Cl- in the soil were also decreased evidently. Compared with ordinary water, magnetization water can increase ginned cotton by 144.7 kg/hm2, and raise income by 2025. 8 yuan/hm2. So magnetization water dripping irrigation can increase the cotton production and income.