OBJECTIVE: To investigate the chemical components and microstructure of Nengchi Bajin ashes which are adjuvant material in the refining of Tibetan medicine gTSo thal, in order to explore the material basis of the refining of gTSo thal.METHOD: Scanning electron microscope-energy dispersive spectrometer (SEM-EDX) and X-ray diffraction (XRD) were used to measure the Nengchi Bajin ashes. RESULT: SEM-EDX analysis show that except of themselves elements of Nengchi Bajin ashes, Nengchi Bajin ashes contain the major elements, such as S, O, C and so on, also contain small amount other elements. XRD analysis show that the structures are AuPb2, PbO (tetragonal and orthorhombic) and Pb in gold ash, Ag2S and PbO in silver ash, Cu1.98 (Zn0.73 Fe0.29)Sn0.99 S4, CuS, SiO2, NaCu2S2 and Ca (Fe(+2), Mg) (CO3)2 in bronze ash, Cu7S4 (orthorhombic and monoclinic) and CuO in red copper ash, Cu7 S4, PbS, ZnS, CaCO3and NaCu2S2 in brass ash, FeS, Fe+2 Fe(2+3)O4 and SiO2 in iron ash, SnS and SiO2 tin ash, PbS, PbSO4 and SnS2 in lead ash. CONCLUSION: We have acquired the datum of elements and microstructure of Nengchi Bajin ashes by SEM-EDX and XRD techniques, and that is benefit to explore the material basis of refining gTSo thal.