A series of catalysts derived from Keggin-type heteropoly compounds (HPCs) were prepared and used as catalysts for the reaction of indole with benzaldehyde to afford bis(3-indolyl)phenylmethane. The results showed that the difference in catalytic activity of HPCs in this reaction depends on the number of introduced vanadium atoms in H3+nPMo12-nVnO40, kind of support, cesium content in CsxH3-xPW12O40 and nature of the metal cation in [(n-C4H9)(4)N]((7-n))PMo2W9(Mn+center dot H2O)O-39. The product yield was strongly dependent on the acidic characteristics which, in turn, depend on chemical composition of catalysts. In the presence of H3+nPMo12-nVnO40 and CsxH3-xPW12O40, the catalytic activity and acidity decreased with increasing V atom or cesium content. Among supported H3+nPMo12-nVnO40. H5PMo10V2O40/gamma-Al(2)O3 is a weaker catalyst than bulk one. [(n-C4H9)(4)N]((7-n))PMo2W9(Mn+center dot H2O)O-39 catalysts exhibit a high electron-acceptor character and interesting structural and coordination properties. Catalytic activity of these Compounds is related to the difference in their ability to coordinate substrates. (C) 2009 Published by Elsevier B.V.