Objective:To establish FTIR method of brag-zhun.Method:The technique of FTIR and the method of quick comparison were used to determine and compare crude and processed brag-zhun from Yushu.Result:The IR spectra of crude and processed brag-zhun from Yushu were similar

and the absorption area was divided into four regions:OH stretching vibration absorption at 3 436 cm-1

H2O bending vibration absorption at 1 628 cm-1

C-O stretching vibration absorption at 1 425-712 cm-1 and Si-O stretching vibration absorption at 400-550 cm-1.The semblance of brag-zhun with LiI

CaCl2 · 2H2O and tachyhydrite respectively was 89.75%

89.75% and 87.23%.Conclusion:The technique of IR was provided for classification and identification of brag-zhun.