Abstract: The 0-3 piezoelect ric composites were fabricated with the polyurethane ( PU) doped with polyaniline( PANI) by in si tu polymerization as mat rix and lead zirconate titanate ( PZT) as function phase. The polarizationand elect rical properties of the composites were studied. The result s show that the polarization and piezoelect ricproperties of 0-3 composites can effectively increase with an appropriate volume f raction of PANI. The piezoelect ricconstant ( d₃₃ ) and elect romechanical coupling coefficient ( k_p ) rapidly increase with increasing the PANI content . Atthe PANI volume f raction of 4 % the d₃₃ and k_p of the composite are 34 pC/ N and 0.25 , respectively , and show themaximum values. The dielect ric constant and dielect ric loss of the composites rise with increasing the content ofPANI.