Abstract: The dried constant weight powders of Angelica Sinensis Radix,Rehmanniate Radix and its compatibility at a ratio of 1∶1 were obtained by spray-dried method.The near-infrared diffuse reflectance spectroscopy (NIRDRS) fingerprints of 90 batches of samples were collected by integral diffuse reflectance method.Three kinds of NIRDRS fingerprints were analyzed by differential spectra analysis of original spectra,first derivative and second derivative spectra,and were classified and identified by principal component analysis (PCA).The results showed that the characteristic peaks and trends of common model of three kinds of NIRDRS fingerprints were similar,but its absorbance difference was obvious.The differences of characteristic absorption peaks before and after compatibility were obtained by differential spectra analysis.PCA showed that three kinds of NIRDRS fingerprints can be clearly classified and aggregated.The compatibility of Angelica Sinensis Radix and Rehmanniate Radix at a ratio of 1∶1 showed some new functional groups,and some functional groups disappeared or decreased,and the wave number ranges changed before and after compatibility were 8639-8091,7509-7205,6550-6439,6202-6011,5780-5746,5512-5394,5386-5026 cm^-1,and 4393-4162 cm^-1.

Key words: Angelica Sinensis Radix, Rehmanniate Radix, compatibility, near-infrared spectroscopy, derivative differential spectra, fingerprints, principal component analysis