This article presents a strategy for the fabrication of hollow poly(N-isopropylacrylamide) (PNIPAM)-Ag nanocomposite spheres. In this approach, the thermosensitive PNIPAM hollow spheres were first synthesized via a one-pot "self-removing" process and then used as supporters for the coordination and in situ reduction of Ag+ ions. The results show that these hollow PNIPAM-Ag nanocomposite spheres still have typical thermal sensitivity, and importantly, these spheres have very good and controllable catalytic activity with five stages of variation versus temperature. (C) 2009 Wiley Periodicals, Inc. J Polyrn Sci Part A: Polym Chem 47: 4919-4926, 2009