The bulk screening being the only possibility for decreasing residual depolarization field and stabilizing tailored domain structures is one of the main factors defining the domain kinetics in ferroelectrics. The bulk screening process was studied in lithium tantalate with lithium stoichiometry [Li]/([Li] + [Ta]) = 48.9%. The main parameters of bulk screening process were extracted from experimental data and compared with those of other representatives of lithium tantalate family. The linear dependence of the maximal value of bulk screening field on lithium stoichiometry was confirmed. The same stretched exponential power indicated that the underlying mechanism of bulk screening process did not change.