The sulfides of MCuSbS₃ and MCuBiS₃ (M=Pb, Eu, Yb) kind have been synthesized for the first time and their some physico-chemical properties have been studied. It has been determined that obtained compounds crystallize in rhomb: PbCuSbS₃ – а=8.160, b=8.72, с=7.8 Å; EuCuSbS₃ – а=8.156, b=8.68, с=7.786 Å; YbCuSbS₃ – а=8.15, b=8.64, с=7.76 Å; EuCuBiS₃ – а=11.28, b=11.62, с=4.00 Å; YbCuBiS₃ – а=11.26, b=11.58, с=3.96 Å. The thermodynamics functions of obtained compounds have been calculated by calculation method