The electronic structures of doped Sb2O5 by IV-family elements (Si, Ge and Sn) were examined using the density function theory (DFT). Density of states (DOSs) results showed that the substituted IV-family elements act as acceptors in Sb2O5. Partial DOSs indicates that by substituting Ge(GeSb) or Sn(SnSb), there may be a larger contribution to the total DOSs near EF than by substituting Si, which suggests that doping Ge or Sn in Sb2O5 produces better ptype doping compared to doping Si. Formation energy results show that IV-family elements are more likely to exist in the substituted position rather than in the interstitial position in Sb2O5, decreasing any self-compensation effect and making it easier for IV-family elements to realize ptype doping in Sb2O5. Ionization energy results show that GeSb or SnSb, two among the three impurities considered, act as shallow acceptors in Sb2O5, thus producing a higher concentration of holes.