A series of experiments were designed to utilize the Taguchi method for investigating the effects of important parameters on the synthesis of NaX zeolite and to find the best conditions of synthesis. An L9 orthogonal design of Taguchi approach was applied to design experiments consisting of 9 trails. The effect of molar composition, including SiO2/Al2O3 and Na2O/Al2O3 ratios, and the crystallization conditions, including temperature (T) and time (t) on crystallinity and also phase purity of NaX zeolite were investigated. The results revealed that the temperature of crystallization and alkalinity (Na2O/Al2O3) of initial mixture were the most influencing parameters for desirable synthesis of NaX zeolite. To examine the validation the result of Taguchi experiment design, the most crystalline sample was resynthesized and characterized by XRD, SEM and N2 adsorption-desorption methods. At the end, the capability of the obtained sample for CO2 adsorption was determined by the static volumetric method.