Abstract: The equilibrium geometry, vibrational frequency of InVO_x(x=1~5) clusters are studied using density functional theory with B3LYP method. The results indicate that the geometric configurations of ground states for InVO_x(x=1, 2) are planar and that for InVO_x(x=3~5) are stereoscopic. The stability for the ground-state structures of InVO_x(x=1~5) clusters is analyzed in terms of their averaged atomic binding energy (E_b), second-order differential energy (Δ²E), the energy gaps(E_g) between the HOMO and LUMO levels, and the dissociated energy (E_d). The results show that InVO₃ cluster is the magic number cluster for this cluster series. Compared with the stability of VO_x(x=1~5) clusters, the stability of InVO₃ cluster is enhanced and that of InVO_x(x=1, 2, 4, 5) cluster is debased slightly. InVO_x(x=2, 3, 5) shows lower chemical activity than VO_x(x=2, 3, 5) and InVO_x(x=1, 4) shows higher chemical activity than VO_x(x=1, 4). In stero geometric configurations, the chemical reactivity of InVO₄ cluster is the strongest among them.