0.30Pb(Lu1/2Nb1/2)O-3-xPb(Ni1/3Nb2/3)O-3-(0.70-x)PbTiO3(PLN-PNN-PT)　ceramics　with　various　PNN　contents　were　prepared　using　a　modified　two-step　columbite　precursor　method　and　characterized　by　X-ray　diffraction　(XRD),　ferroelectric　and　dielectric　measurements.　The　composition　of　0.30PLN-0.31PNN0.39PT　exhibits　excellent　physical　properties　with　d(33)　=　366pC/N,　Tc　=　214　degrees　C,　epsilon＇　=　3076,　tan　delta　=　0.0225,　Pr　=　32.89　mu/cm(2)　and　Ec　=　15.23KV/cm.　The　values　of　relaxor　factor　gamma　approaches　2　indicating　diffuse　character　of　PLN-PNN-PT　ceramic.　The　dielectric　behavior　was　discussed　based　on　Curie-Weiss　Law　and　Lorentz-type　quadratic　relationship.　A　transformation　from　relaxor　ferroelectric　to　normal　ferroelectric　was　demonstrated　with　PT　content　increasing　in　this　ternary　system.　(C)　2017　Elsevier　B.V.　All　rights　reserved.