The electronic structures of Keggin-type heteropolyanions (SiMo12O40)^4^-, (GeMo12O40)^4^- and (AsMo12O40)^3^- have been calculated by the SCC-DV-Xα method. According to the comparison among calculating results of the three heteropoly anions and those of (PMo12O40)^3^- which were adapted from the literature, we discussed the influence of the central atoms on the electronic structures and catalytic properties of Keggin structure anions. The results show that the influences of the central atoms on electron cloud, electrostatic potential, total density of states are not clear. But the central atom can affect the components of the frontier orbitals HOMO and LUMO. The relative sequence of energy of LUMO and Fermi level is as follows: (AsMo12-O40)^3^->(PMo12O40)^3^->(GeMo12O40)^4^->(SiMo12O40)^4^-. The sequences of oxidation and catalytic activity are the same as the above. For (XMo12O40)^n^- (X=P, Si, Ge), Ot (terminal oxygen), Ob (bridge oxygen), Ox (central oxygen), Mo and X have the potential to participate in the catalytic reactions, whereas to (AsMo12O40)^3^-, just As and Ob are exclusively active.

Key words: HETEROPOLYACID, SILICIC ACID P, ELECTRONIC STRUCTURE, MOLYBDIC ACID P, ARSENIC ACID P, GERMANIC ACID, CATALYTIC BEHAVIOUR