Dispersion and aging behavior of commercial BaTiO3 and PZT powders in water were studied by means of sedimentation, electrophoretic mobility, conductivity, and diffuse reflectance infrared Fourier transform spectroscopy (DRIFT). It is found that BaTiO(3)has an IEP at pH 10, while the IEP of PZT is at about pH 7, at which the lowest sedimentation density is observed. The results also show that there is an obvious difference of dispersion and aging behavior between BaTiO3 and PZT suspensions: the suspensions of PZT were much more stable than those of BaTiO3 in water.