This article describes a new strategy of fabricating multifunctional textile through in situ synthesis of polymer-hybrid nanoparticles in the fabric by a one-step microwave irradiation. The amino-terminated hyperbranched polymer (HBP-NH2) was employed as the smart polymer, which not only can entrap silver ions and reduce them for the in situ generation of Ag nanoparticles, but also react with zinc ions to produce ZnO nanoparticles. Therefore, the two kinds of nanoparticles could be in situ fabricated in textile simultaneously under the control of HBP-NH2. Cotton fabric was chosen for this study. The mechanism of the multifunctional finishing process of cotton fabric was discussed in detail. The treated cotton fabrics were characterized, and the ultraviolet (UV) protective properties and antibacterial activities of them were investigated in comparison with the cotton fabric treated with only one kind of nanoparticle. The results indicated that the nanoparticles were assembled on cotton fibers with size range from 20 to 100 nm. The multifunctional finishing could offer cotton fabric with excellent UV protective property and antibacterial activity simultaneously. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3778-3784, 2013