Good quality barium bismuth titanate (BaBi4Ti4O15) ceramics is fabric ated successfully with BaBi4Ti4O15 nanopowders prepared by Sol-Gel p rocess. The ferroelectric to paraelectric phase transition of barium bismuth titanate ceram ics was studied by determining the dielectric and saturated ferroelectric proper ties of barium bismuth titanate. All measurements show barium bismuth titanate m ay be a kind of order_disordered relaxor ferroelectrics with a diffused phase transition which is a firstordered one, and its dielectric and saturated fe rroelectric properties depended strongly on its lattice structure.