A series of new 3,3,3-trifluoropropyl substituted copoly(carbosiloxane)s have been prepared by Pt-catalyzed step-growth hydrosilylation copolymerization of 1,9-dihydrido-1,1,3,5,7,9,9-heptamethyl-3,5,7-tris(3',3',3'-trifluoropropyl)pentasiloxane (I) with various alpha,omega-divinylsilanes and siloxanes. The structures of the copoly(carbosiloxane)s have been determined by H-1, C-13, Si-29, and F-19 NMR as well as IR spectroscopy. The molecular weight distributions (M-w/M-n) of the copolymers have been characterized by GPC and their thermal properties measured by DSC and TGA.