In the present study, midinfrared spectroscopy(MIR) was attempted to apply for quality evaluation of C. deserticola. First of all, IR spectra of the herbal sample and its 3 main extracts including PeGs, Man and Polysaccharides were compared. Characteristic absorption peaks within different wave number range were found in different extracts. Then the authors managed to find the relationships between the intensity of the characteristic peaks and the relative content of the PeGs and Man in herbal sample. The IR spectra of the herbal samples were compared with PeGs and Man using Spectrum v5.02 software (Perkin Elmer) for IR Corrdations. It was found that the content of PeGs (y) and its IR Correlation (x) within herbal sample in the range of 1800~1200cm-1 〖JP2〗were correlative (R2= 0.9927) by the SPSS 11.0 analysis, and the regression equation is y=19.846x + 0.0623. In the same way, the content of Man (y) is correlative with the IR Correlation (x) in the range of 1100~ 600cm-1 (R2 =0.9705), and the regression equation is y=13.855x-0.1714. Therefore, MIR spectroscopy is a fast and effective method in qualitative and semiquantitative analysis of quality evaluation of C. deserticola.