Here, ultrasound-assisted extraction with ultrasonic probe of total polyphenolic content from leaves of cornelian cherry (Cornus mas L.) was studied. Batch adsorption was carried out to concentrate polyphenol extract using bentonite/2-(dimethyl amino) ethyl methacrylate composite adsorbent. The extraction was optimized through face central composite design combined with response surface methodology. It was found that bentonite/2-(dimethyl amino) ethyl methacrylate composite exhibits significant adsorption capacity (2407.50 mg-GAE/g-bentonite/2-(dimethyl amino) ethyl methacrylate composite) for polyphenols in cornelian cherry leaves. It was observed that pH was the crucial factor and highest adsorption capacity was obtained at pH 10.