Several experiments were conducted to examine the effects of the molecular weight of polyesters formed by polymerization of citric acid and ethylene glycol on the development of phase formation and agglomerate of Zr-riched lead zirconate titanate Pb (Zr0.95Ti0.05) O3 powders prepared by the Pechini method. Evolvement of the chelation of citric acid and metallic ions was detected by FTIR spectroscopy. Phase behavior and morphology of powders calcined at temperature range of 400 to 800℃ for 2h were studied by powder X-ray diffraction and scanning electron microscopy. The molar ratio of citric acid and ethylene glycol could affect the chelation between carboxylate groups and metallic ions but had no effect on the formation of Pb (Zr0.95Ti0.05) O3. Higher molecule weight of polyester formed from citric acid and ethylene glycol could help the formation of the final crystalline phase and gave soft agglomerate particles of Pb (Zr0.95Ti0.05) O3 powders.