Polarization switching behavior and energy storage performances of (Pb1-xLax)(Zr0.90Ti0.10)(1-x)/O-4(3) (PLZT x/90/10) ceramics with La compositions across the ferroelectric/antiferroelectric phase boundary, which show variable amount of antiferroelectric (AFE) orthorhombic and ferroelectric (FE) rhombohedral phases, were investigated. A low AFE to FE switching field was obtained and its value could be adjusted by La chemical modification. While the PLZT system evolves from a FE state to an AFE state as a function of La content and from an AFE state to a FE state as a function of the applied electric field, the recoverable energy (W-re) and loss energy (W-loss) range between two limits whose lower and higher values are obtained for PLZT composition in AFE state and FE state, respectively. In terms of the extent of La-modification, the Wre has been enhanced from 0.819 J/cm(3) (for PLZT 2/90/10 and electric field of similar to 30 kV/cm) to the highest value of 1.85 J/cm(3) (for PLZT 3.5/90/10 and electric field similar to 65 kV/cm), followed by their subsequent reduction.