One of the promising ways of designing new single-phase multiferroic materials is adjusting the temperatures of both ferroelectric and magnetic phase transitions by ion substitutions in the host compound to obtain the maximal magnetoelectric coupling. The aim of the present talk is a brief review of the recent studies of both ferroelectric and magnetic phase transitions in some Fe containing ternary perovskite multiferroics, especially PbFe0.5B0.5O3 (B-Nb, Ta, Sb) and related solid solutions.