The superconducting transition temperatures Tc of systems V2Hf1-xNbx,V2Zr1-xNbx and V2Hf0.5Zr0.5-xNbx were studied. We found that Nb content influences SC Tc of V2Hf0.5Zr0.5-xNbx in a different way from that of V2Hf1-xNbx and V2Zr1-xNbx. X-ray photoelectron spectroscopy of V2Zr, V2Hf and V2Hf0.5Zr0.5 showed that the coexistence of Zr and Hf atoms in A sites of AB2 compounds results in a new type of electron density transfer enhancing the interaction of atoms. This fact supports the following explanation to Tc behavior: 4d-5d coordination of V2(HfZr) may favor the hybridization of 4d conduction band thus causing higher Tc.