Silicone resins are of high-performance LED encaps-ulant mainly owing to their excellent discoloration resistance against heat and UV irradiations.But they alsohave some obvious disadvantages, such as weak in adhesion and mechanicalproperties.One more main shortage ofsilicone resins as LED encapsulant is their relativelylowrefractive index (RI),which results in a relativelylow luminescence efficiency of LED devices.So it is important to improve their RI through physical or chemical approaches.Silicon-phenyl groups are usually introduced into silicone resins to increase their refractiveindex.However,the RI of silicone resins with silicon-phenyl groups is limited to be lower than1.55.In orderto achieve a higher RI,silicon-naphthyl groups are introduced, and silicone resinwith a RI of 1.58 is synthesized in this paper.