The purpose of this study was to improve the physical properties and to expand the application range of starch-based blend films added nano-sized TiO2/poly(methyl methacrylate-co-acrylamide) (PMMA-co-AM). Starch-based blend films were prepared by using corn starch, polyvinyl alcohol (PVA), nano-sized PMMA-co-AM, nano-sized TiO2/PMMA-co-AM particles, and additives, i.e., glycerol (GL) and citric acid (CA). Nano-sized PMMA-co-AM was synthesized by emulsion polymerization and TiO2 nanoparticles were also prepared by using sol gel method. Nano-sized TiO2/PMMA-co-AM particles were synthesized by wet milling for 48 h. The morphology and crystallinity of TiO2, nano-sized PMMA-co-AM and TiO2/PMMA-co-AM particles were investigated by using the scanning electron microscope (SEM) and X-ray diffractometer (XRD). In addition, the functional groups of the TiO2/PMMA-co-AM particles were characterized by IR spectrophotometry (FTIR). The physical properties such as tensile strength (TS), elongation at break (%E), degree of swelling (DS), and solubility (S) of starch-based films were evaluated. It was found that the adding of nano-sized particles can greatly improve the physical properties of the prepared films. The photocatalytic degradability of starch/PVA/nano-sized TiO2/PMMA-co-AM composite films was evaluated using methylene blue (MB) and acetaldehyde (ATA) as photodegradation target under UV and visible light. The degree of decomposition (C/C-0) of MB and ATA for the films containing TiO2 and CA was 0.506 and 0.088 under UV light irradiation and 0.586 (MB) and 0.631 (ATA) under visible light irradiation, respectively. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 1850-1858, 2011