Water is the most essential element for durability and survival of environment to the extent that a human cannot alive without water more than three days. Given the importance of water and the daily growth of the world’s population, the challenge for the society will be to provide safe water. According to the United Nations, clean water was known as a fundamental right for humans and international societies and governments have the responsibility to provide this. One of the most important factors that may change water safety is salinity which is recognized as a factor that indicates the presence of water-soluble salts. This factor is determined as Electrical Conductivity (EC). The Salinity of potable water that affects the taste of water, reduces the tendency of the water usage, has undesirable effects during treatment, water treatment plant facilities, and network utilization, and also affects plant growth. Therefore, having access to fresh and clean water for drinking, health, agriculture and the industry (nationally or globally) should always be a key priority. For this purpose, brackish and saline water can be considered as a source of water supply and are approved among select important strategies and develop desired goals that is to provide fresh water. According to the description provided, the aim of this research is to investigate a new approach with lower cost and lower energy consumption compared to the conventional methods as a Capacitive Deionization (CDI) that is tested in order to remove salt and decrease the electrical conductivity of water. In this method by making input feed solution with sodium chloride and preparing the electrodes were covered with Activated Carbon Clothes (ACC), CDI system was launched as a batch reactor and after doing preliminary tests and investigating numerous factors on the efficiency of desalination process by the CDI method, the effect of four parameters such a duration of tests, initial concentration of feed solution, applied voltage, and pH of the solution on three response including Percentage of EC removal, chloride removal and sodium ion removal was examined. In this study, design of experiments was performed by Response Surface Methodology (RSM) and by the Design Expert V. 9.0.6.2 software. After statistical analysis by the software and offering a fit model based on results, extreme reliance of the responses on the initial concentration of salt in feed solution and lack of dependence on the applied voltage in defined range in tests was observed. As a numerical report the maximum efficiency of EC removal, Cl - removal, and Na + removal was obtained about 57%, 70% and 25% respectively. Finally, to assess this research the results of the tests were compared to the results of common adsorption process with activated carbon and also with one of the previous researches. The result of this comparison indicates that this recent research has more than fifty percent ability in removal of EC compared to the two cases mentioned in spite of spending less time and cost. Thus, the use of CDI method in order to desalinating brackish water or water with low and moderate salt concentration ca be introduced as an affordable method and if further improve more than now, it will be more effective than common methods. Key Words Fresh water, Electrical Conductivity (EC), Brackish water, Desalination, Activated Carbon Cloth (ACC), Capacitive Deionization (CDI), Response Surface Methodology (RSM).