Adsorption equilibrium experiments of phenol on NKA II resin were separately conducted in the presence and absence of ultrasound at ambient temperature. The isotherm of phenol on the polymer adsorbent in the presence of an ultrasonic field is reported. Results indicate that the adsorption of phenol determined in the presence of ultrasound is less than that in the absence of ultrasound. In addition, experimental results also show that the use of ultrasound in the adsorption system of the phenol aqueous solution + NKA II resin could cause a rise in temperature of the system. The effect of ultrasound on the isotherm of phenol on the NKA II resin is due both to the thermal and non-thermal effects of the ultrasonic field, and the role of the latter is much greater than that of the former. The addition of surfactant substance, ethanol or ethyl acetate, to the adsorption system of the phenol aqueous solution + the NKAII resin in the existence of the ultrasonic field would cause the equilibrium adsorbed amounts of phenol to decrease.