Bismuth layer structured piezoelectric ceramics Na0.5Bi4.5Ti4-2xNbxTaxO15(NBTNTx, 0≤x≤0.06) were prepared by using the solid state processing. The effects of the different amount of Nb and Ta modification on the microstructure and electrical properties of Na0.5Bi4.5Ti4O15 ceramics have been investigated. The results reveal that all of the samples have a pure Aurivillius type structure. The sizes of the grain become small and unanimity with a moderate addition of Nb and Ta, while the σand tan δ of the Na0.5Bi4.5Ti4O15 ceramics are reduced. The Curie temperature (TC) decreases with the addition increase of Nb and Ta. The TC of all the samples is above 610 ℃. When x=0.02, the ceramic exhibited optimum electrical properties:d33=17 pC/N, kp=4.19 %,kt=18.10%,Qm=3 527,Pr=10.50 μC/cm2.