High-temperature vulcanized silicone rubber was prepared by using allyl-capped carbosilane dendrimers, in which the code molecules were Si(CH2CH=CH2)(4) and Ph2Si(CH2CH=CH2), as crosslinker and nanoscale reinforcing filler, respectively. Allyl-capped carbosilane dendrimers improved the mechanical properties of silicone rubber. The optimum tensile strength and tear strength were 9.6 MPa and 31.0 kN/m, respectively, when using SiG(n(allyl)m) as the crosslinker and 10.1 MPa and 32.0 kN/m, respectively, when using Ph(2)SiG(n(allyl)m) as the crosslinker. (c) 2006 Wiley Periodicals, Inc.