Abstract: AIM: To assign the ¹HNMR finger prints of the roots of Polygonum cuspidatum, Polygonum multiflorum, Rheum palmatum and Rheum tanguticum, and to compare the differences of the ¹HNMR finger prints between Polygonum and Rheum species. METHODS: After the characteristic chemical constituents of the extracts of the above traditional Chinese herbal medicines isolated by silica gel column chromatography and crystallization, their ¹HNMR spectra were investigated, and the characteristic signals of every ¹HNMR finger prints were assigned. RESULTS: Physcion was isolated from the characteristic general extracts A of the roots of P. cuspidatum and P. multiflorum , physcion-8-O-β-D glucoside from extracts B of the above two species, and chryxophanol and physcion from extract A of the roots of R. palmatum and R.tanguticum. The ¹HNMR finger prints of the roots of P.cuspidatum and P. multiflorum which belong to the same genus had high similarity and showed mainly the characteristic signals of physcion. On the other hand, owing to the ratio discrepancy of the major similar constituents, the relative intensity of ¹HNMR signals showed obvious differences. The ¹HNMR finger print B of P. cuspidatum showed mainly the characteristic signals of physcion-8-O-β-D glucoside, but similar signals were not observed from the same extract of P. multiflorum. Both the same aspects and the essential differences could be observed from the ¹HNMR finger prints of the Rheum and Polygonum species. CONCLUSION: The ¹HNMR finger prints might be utilized for the identification of the roots of P. cuspidatum and P. multiflorum, Rheum palmatum and Rheum tanguticum, and the classification of Polygonum and Rheum species.