Abstract: OBJECTIVE To establish a rapid quantitative method for determining main saponin constituents in Panax notoginseng by near-infrared spectroscopy (NIR).METHODS A total of 173 batches of Panax notoginseng samples with different sizes,from different parts and geographical regions were collected,and the contents of notoginsenoside R₁,ginsenoside Rg₁,Re,Rbsub>1 and Rd as reference were quantitatively determined by HPLC.The crushed samples of Panax notoginseng were used to obtain the NIR spectra of 4 000-10 000 cm^-1.Model parameters including pretreatment of spectra,wavelength range and PLS factors were optimized.Partial least squares regression (PLSR) was employed to establish the calibration models between the spectra and the contents of main active constituents,respectively.RESULTS In the constructed PLS models,the values of correlation coefficient (r) of notoginsenoside R₁,ginsenoside Rg₁,Re,Rbsub>1 and Rd were 0.959 6,0.978 5,0.902 6,0.966 0 and 0.992 9,respectively.CONCLUSION The constituents determined by this method are the main active constituents of Panax notoginseng,which are also the quality assessment markers for the preparations derived from the total saponins of Panax notoginseng.The proposed method is rapid,convenient and accurate,which can be used for the rapid analysis of the main active constituents in Panax notoginseng.