The phase equilibria in the YbTe–Sb 2 Te 3 –Bi 2 Te 3 quasi-ternary system were investigated by means of differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscope with energy dispersive analysis (SEM-EDS) techniques. Two isothermal sections of the system at 300 and 850K, the projection of the liquidus surface as well as several isopleth sections were experimentally carried out. The boundary quasi-binary sections YbTe–Bi 2 Te 3 and YbTe–Sb 2 Te 3 restudied and existence of the four ternary compounds YbSb 2 Te 4 , YbSb 4 Te 7 , YbBi 2 Te 4 and YbBi 4 Te 7 reported earlier were not confirmed. Along the boundary Sb 2 Te 3 –Bi 2 Te 3 system the existence of continuous solid solubility field with the tetradymite type crystal structure was revealed at 300 and 850K.