This study is related to the investigation of the characteristics of quaternary ammonium salt catalysts on the addition reaction of phenyl glycidyl ether and dichlorodiphenylsilane to form silyl ether Quaternary ammonium salts have good yield of silyl ether. Among the salts tested, the ones with higher alkyl chain length and more nucleophilic counter anion showed a higher catalytic activity. The catalytic activity increased with temperature. In order to facilitate the recovery of catalyst, polymer-immobilized catalysts were also used as catalyst.