In this work, a series of siloxane epoxy resins (E3074) were synthesized through reaction of poly(methylphenylsiloxane) (DC-3074) with epoxy resin. The chemical structure of the resultant epoxy resin was determined by FTIR, GPC, and epoxy equivalent weight (EEW) tests. The mechanical measurements indicated that the tensile strength of E3074 was lower than that of neat epoxy resin after modification, while their elongations at break improved markedly when compared with that of epoxy resin. SEM revealed that the particle size of silicone had a significant effect on the mechanical properties of the modified epoxy resin. TGA results showed that the thermal stability of E3074 serials was better than that of epoxy resin. The char residue of E3074 at 600°C increased with the incremental content of silicone. DMA tests displayed that the addition of silicone effectively enhanced the damping properties of epoxy resin. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40212.