A novel allyl-ended hyperbranched organic silicone resin (AHSR) was prepared successfully by hydrosilylation between phenyltriallylsilane and 1,1,3,3-tetramethyl disiloxane with halloysite-supported platinum (Pthalloysite) as the catalyst. The chemical structure of the AHSR was characterized by 1H-NMR and Fourier transform infrared spectroscopy, and its molecular weight was determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The Pthalloysite catalyst was prepared from chloroplatinic acid and halloysite by the simple wet impregnation method. The transmission electron micrographs of the catalyst showed that the platinum dispersed homogeneously into the halloysite nanotubes. Compared with the traditional homogeneous Speier and Karstedt catalysts, our heterogeneous Pthalloysite catalyst demonstrated a higher catalytic activity, which was confirmed by IR monitoring of the attenuation of the Si?H stretching band. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012