Electrocaloric effect (ECE) of pure and modified PbSc 1/2 Ta 1/2 O 3 (PST) and its solid solutions and PbMg 1/3 Nb 2/3 O 3 - PbTiO 3 ferroelectric ceramics is studied at different temperatures and external electric field intensities. High value of (ECE) up to 2.3 K is observed in PST ceramics at modification in B sublattice by Co 3+ and Sb 5+ ions. The features of ECE in PST are explained by significant structure rearrangement at electric field induced Fm3m M R3m phase transition and high long range ordering of B ions in the ABO 3 perovskite structure. A further increase of ECE is observed in ceramic multilayer capacitors at higher electric field intensities up to 138 kV/cm.