OBJECTIVE: To establish HPLC fingerprint of Mongolian medicine Ramulus Tamarix, and to conduct similarity evaluation and cluster analysis. METHODS: HPLC method was adopted. The determination was performed on Agilent ODS C18 column with mobile phase consisted of methanol-water (gradient elution) at the flow rate of 1.0 mL/min. The detection wavelength was set at 335 nm, and column temperature was 30 ℃. The sample size was 10 μL. Using quercetin peak as reference, HPLC fingerprint of 10 batches of medicinal sample were drawn. Similarity evaluation was conducted by using Similarity Evaluation System for Chromatographic Fingerprint of TCM (2004 A) so as to confirm common peak. SPSS 17.0 software was used for cluster analysis of those samples. RESULTS: There were 13 common peaks in HPLC fingerprint of 10 batches of samples, and the similarities of them were all greater than 0.95; 2 common chromatographic peaks of quercetin and kaempferol were identified. Results of cluster analysis showed that 10 batches of samples were classified into 2 classes. S8 was clustered into one class; other were clustered into another class. CONCLUSIONS: Established HPLC fingerprint and results of similarity evaluation and cluster analysis can provide reference for quality control of R. Tamarix.