0.7BiFeO3-0.3BaTiO3+x%Sb2O3 (mass fraction) ceramics (BFO-BTO+xSb, x=0.00~0.20) were synthesized by the conventional solid state reaction method, and the effect of Sb2O3 doping on the crystalline phase structure, dielectric, conductive, piezoelectric and ferroelectric properties of BFO-BTO ceramics was investigated, along with doping mechanism. The results indicate that Sb doping change the crystal structure from a pesodocubic lattice to a rhombohedral lattice. Sb substitution for B site increases ferroelectric relaxation, decreases dielectric loss at high temperature, and also lowers the Curie temperature. The conductive characteristics demonstrate that Sb doping changes the concentration of V×O and Fe2+, and decreases the conductivity, without changing the conductive mechanism with oxygen vacancy as the dominant carrier. BFO-BTO+xSb ceramics exhibit optimum electric properties at x=0.05: d33=213 pC/N, kp=28.8%, Qm=38, Tc=520 ℃, Pr=24.7 μC/cm2.