Abstract: OBJECTIVE To conduct the removal of K⁺ in traditional Chinese medicine decoction of Shenshuai Recipe by using the medicinal cation exchange resin(sodium polystyrene sulfonate). METHODS The concentration of K⁺ and Na⁺ in the decoction were determined by the ICP-MS method. And the UPLC method was established to determined the impact of K⁺ removal technique on indicative compounds in the decoction. After investigating the resin properties, static adsorption of cation exchange resin was applied in the study. It was preliminarily determined that the factors affecting K⁺ removal was temperature, resin amount and adsorption time. The single factor experiment was conducted to investigated the influence of these three factors on K⁺ adsorption in decoction. RESULTS The appropriate process conditions were determined as follows: the temperature was 25 ℃, the amount of resin was decoction︰resin (15 mL︰1 g), and the adsorption time was 1 min. The removal rate of K⁺ was > 80% in decoction of Shenshuai Recipe. The removal rate of K⁺ was 62.5%-80.3% in other decoction of renal disease prescription. This technology was greatly reduced the intake of K⁺through decoction in patients with renal failure. In addition, it was found that the adsorption effect of this medicinal resin on K⁺ was greatly affected by the ion environment, and this kind of resin was also selective for the adsorption of different indicative component. CONCLUSION The establishment of this process of K⁺ removal can well reduce K⁺ in the decoction of Shenshuai Recipe.