X-ray powder diffraction was used to analyze and evaluate 11 samples of traditional Chinese medicine, Costustoot, found at various locations in China. A reference fingerprint pattern with 48 characteristic peaks for Costustoot was obtained from X-ray diffraction patterns of six Costustoots from the rhizomes of Aucklandia lappa Decne. The reference fingerprint pattern with 48 characteristic peaks for Costustoot was then used to evaluate the remaining five Costustoot materials. X-ray diffraction results show that the X-ray diffraction Fourier fingerprint pattern method can be used for rapid classification, identification, and quality control of Costustoots.