In this work, a novel method was used to prepare carbon modified ZnO nanoparticles. The nanoparticles were coated with a layer of poly(methyl methacrylate) by gamma radiation firstly, and then the coated nanoparticles were annealed in air. The polymer was burned and carbon was left on the surface of ZnO nanoparticles. A stable blue luminescence peak (similar to 420 nm) can be observed for the carbon modified ZnO nanoparticles. The carbon modified ZnO nanoparticles were also investigated by X-ray photoelectron spectroscopy. The origin of the blue emission was discussed. The blue PL is related to the left carbon. This novel method also can be used to prepare other carbon modified nanoparticles. (c) 2006 Springer Science+ Business Media, Inc.