X ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy energy dispersive spectromete and nuclear magnetic resonance were used to study the effect on chemical structure of geopolymer by copper. Geopolymer was prepared from silicon fume, metakaolin, potassium hydroxide and water. Copper was added into geopolymer in the form of nitrate. Vibration frequencies of Al—O—Si chemical bond and Si—O—Si chemical bond were slightly affected by copper. Chemical shifts in 27Al NMR and 29Si NMR spectra were slightly affected, however, vibration modes of chemical bonds, tetrahedron units and their inter linkage types were not affected by copper.