In this article, the copper-gallium (Cu-Ga)/poly(acetoacetoxyethylmethacrylate-styrene) (P(AAEM-St)) nanocomposites were prepared and characterized according to the following steps. Firstly, Cu-Ga/P(AAEM-St) nanocomposites were prepared via emulsifierfree emulsion with metal Ga in copper acetate solution and copolymerization of St and AAEM monomers by ultrasonic under nitrogen protection. Secondly, the constituent, i.e., the interaction between metal nanoparticles and polymeric matrix of the composites, was tested by various techniques including X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, and Xray photoelectron spectroscopy. Cu, Ga, and CuGa 2 phase in polymeric matrix were identified by above techniques. It was revealed that the interaction is a chemical force between Cu atoms belonging to metal nanoparticles and C¼O associated with acetoacetoxy from polymeric matrix.