A new method using near infrared spectroscopy (NIRS) for fast and nondestructive determination of the active components in natural herb is proposed. HPLC was used as a reference method to determine the contents of notoginsenoside RI , ginsenoside Rgj, Ri"i, and Rd in Panax notoginseng herb, with colourimetry for Panax notoginseng saponins (PNS) . The contents of RI, Rg_1, Rb_1, Rd and PNS in the prepared 39 samples ranged in 1.58 -5.08, 21.68-46.13, 11.46-40.41, 3. 38-8.87, 64.22 - 145.13 mg-g~1 powder, respectively. Then, the near infrared diffuse reflectance spectra of the samples were acquired in 3500 - 11000 cm~l. Different wavenumber ranges and 11 spectrum preprocessing methods were investigated according to RMSECV values. Five calibration models were developed to correlate the spectra and the values determined by wet chemical analytical methods. The models were successfully applied to predict 8 unknown samples. RMSECV of the models for R_1 , Rg_1, Rb_1, Rd, PNS were 0.40, 1.47, 1.94, 0.53, 5.15 mg-g-1 herb, and RMSEP were 0.53, 3.15, 2.14, 0.70, 9.03 mg-g-1 herb, respectively. The method is fast, nondestructive and accurate. It provides a new efficient and environmental friendly method for determining the active components of natural herbs.

Key words: near infrared diffuse reflectance spectroscopy, CHINESE DRUG, ADSORPTION RESINS, SAPONINS