Effects of InNbO4 (IN) fabrication on phase purity of the perovskite 23Pb(In1/2Nb1/2)O-3-45Pb(Mg1/3Nb2/3)O-3-32PbTiO(3) (PIN-PMN-PT) were studied. Excess In2O3 and annealing process on the phase of the synthesized IN were investigated. In addition, the precalcined IN and mixed IN powders on the phases of PIN-PMN-PT were discussed. The experimental results indicated that excess In2O3 have has minimal influence on the phase of IN due to the higher chemical activity of In2O3, IN powder with 3% In2O3 excess was in gray color because of the reaction, In2O3In2O, which can be changed to white color by annealing at 850 degrees C in air. It was apparent that the mixed IN would benefit the pyrochlore-free PIN-PMN-PT rather than precalcined IN powders. An optimized way for preparing PIN-PMN-PT materials was also proposed in this article.