In this study, orthoclase and sodium chloride powder were mixed up, and their chemical reaction was carried out at 810℃. The XRF analysis was applied to analyze the chemical composition before and after the reaction quantitatively. Two grams of orthoclase were mixed with 20 g and 40 g powders of NaCl, and the reaction lasted for 12, 24, 36, 48, 72 hours respectively. After mixture with 20 g NaCl, the content of Na₂O in orthoclase varied from 3.35% in original samples to 9.05%, 9.33%, 10.1%, 10.5% and 10.8% in the resultant materials, separately. However, after mixture with 40 g NaCl, the content varied to 9.98%, 10.3%, 10.5%, 10.9% and 11.9% correspondingly in the same time span. Ion exchange velocities for orthoclase slowed down after 12 hours and the quantity of ion exchange increased slowly. The Na⁺ distribution coefficient was calculated according to the formula of ion exchange reaction. The Na⁺ distribution coefficient for molten salt of higher concentration was higher than that of lower concentration in the experiment and the reaction under the condition of higher concentration proceeded more thoroughly. Orthoclase could serve as a good material of ion exchange.