Object To establish a method for chemical pattern recognition on the quality assessment of Radix Astragali. Methods The contents of astragaloside in 18 samples of Astragalus Linn. in different species and origins were determinated by dual-wavelength TLCS method. The developing solvent was CHCl 3-MeOH-H 2O (65∶30∶10,), the UV detection was set at ? s=390 nm; ? R=590 nm. Astragaloside was regarded as the quality assurance of medicinal Radix Astragalus. Based on the TLCS method, the chemical data were obtained. Hierarchical clustering analyses were applied to the chemical pattern recognition. Results The content of astragaloside in Astragalus mongholicus (Bge.) Hsiao and A. membranaceus (Fisch.) Bge. was relatively higher than that in the other samples. This is consistent with the Pharmacopoeia of the People's Republic of China in which the two sorts of Astragalus Linn. were regarded as goods. Conclusion This method is a practicable in the quality assessment of Radix Astragali.