The phase diagram of molten salts of the rare earth system SmCl3-NaCl-CaCl2 has been investigated by DTA. For four liquidus corresponding to the primary crystallization of SmCl3, NaCl, CaCl2 and 2NaCl . SmCl3, five univariant lines related to the secondary crystallization, ternary eutectic point E=376 degrees C (33.1 mol% SmCl3, 46.9 mol% NaCl) and ternary peritectic point P = 389 degrees C (29.3 mol% SmCl3, 52.6 mol% NaCl) were found.