There are provided a composite perovskite powder, a preparation method thereof, and a paste composition for an internal electrode having the same, the composite perovskite powder capable of preventing ions from being eluted from an aqueous system at the time of synthesis while being ultra-atomized, such that when the composite perovskite powder is used as an inhibitor powder for an internal electrode, sintering properties of the internal electrode may be deteriorated, and sintering properties of a dielectric material may be increased; accordingly, connectivity of the internal electrode may be improved, and permittivity and reliability of a multilayer ceramic capacitor (MLCC) may be increased.