Abstract:The phase diagram of tcrnary systen,CaCl₃-BaCl₂-LiCl was researched by DTA and X-rayanalysis.There were 5 liquid surfaces corresponding to CeCl₃, a-BaCl₂,β-BaCl₂,LiCl andBa3CeCl9, respectively and 6 univariant curves corresponding to the secondary crystallization andeutectic point E(65. 8 wt. -% CeCl₃2.5wt -%BaCl₂,33.2wt -%LiCl 452℃)and peritec-tic point P(50.0 wt.-% CeCl₃,22.8wt,-% BaCl₃, 27.2wt -% LiCl; 480℃). At the sametime an unstable compound was found in solid statc and decomposed at 110 ℃.

Key words: system phase diagram CeCl₃-BaCl₂-LiCl