A conducting diatomite was obtained by polyaniline on surface modification of diatomite, and was characterized via Fourier-transform Raman spectra, UV-Vis absorption spectra, thermogravimetric analysis and scanning electron microscope, as well as conductivity. The results of spectroanalysis illustrate that polyaniline is not simply blended with diatomite. An interaction exists at the interface of diatomite and polyaniline, which may associate with hydrogen bond formed between the surface of diatomite with electronegativity and N-H bond in polyaniline macromolecule. The results of thermogravimetric analysis suggest that the conducting diatomite only contains 8% polyaniline by mass, but its conductivity has reached 2.8 x 10(-2) S cm(-1) at 20 degreesC. (C) 2003 Elsevier Science B.V. All rights reserved.