The rare earth (RE=La, Y, Gd) salicylates were synthesized by the rheological phase reaction method. The complexes were characterized by elemental analysis, infrared spectra (IR), X-ray powder diffraction (XRD) and thermal gravity analysis (TG). They can be represented by general formula RE(HSal)3 (RE=La, Y, Gd; HSal=C6H4(OH)COO). The crystals of them are monoclinic and have layered structure. The mechanism of thermal de-composition of rare earth salicylates was studied by using TG, DTA, IR and gas chromatography-mass spectrometry (GC-MS). The thermal decomposition of the rare earth salicylates in nitrogen gas proceeded in three stages: firstly, they were decomposed to form RE2(Sal)3 (Sal=C6H4OCOO) and salicylic acid; then, RE2(Sal)3 were decomposed further to form RE2O(CO3)2 and some organic compounds; finally, RE2O(CO3)2 were decomposed to form rare earth metal oxides (RE2O3) and carbon dioxide. The organic compounds obtained from the second step of the reac-tion are mainly dibenzofuran, xanthenone, 6H-benzo[c]chromen-6-one, 6-phenyl-6H-benzo[c]chromene, and 1,3-diphenyl-1, 3-dihydro-2-benzofuran. The rare earth (RE = La, Y, Gd) salicylates were synthesized by the rheological phase reaction method. The complexes were characterized by elemental analysis, infrared spectra (IR), X-ray powder diffraction The mechanisms of thermal de-composition (RE = La, Y, Gd; HSal = C6H4 (OH) COO). The crystals of them are monoclinic and have layered structure. of rare earth salicylates was studied by using TG, DTA, IR and gas chromatography-mass spectrometry (GC-MS). The thermal decomposition of the rare earth salicylates in nitrogen gas proceeded in three stages: first, they were decomposed to form RE2 ( (CO) 2 and some organic compounds; finally, RE2O (CO3) 2 were decomposed to form rare earth metals oxides (Sal) 3 (Sal = C6H4OCOO) and salicylic acid; RE2O3) and carbon dioxide. The organic compounds obtained from the second step of the reac tion are mainly dibenzofu ran, xanthenone, 6H-benzo [c] chromen-6-one, 6-phenyl-6H-benzo [c] chromene, and 1,3-diphenyl- 1, 3-dihydro-2-benzofuran.