OBJECTIVE： To establish a method for qualitative screening and quantitative determination of indicative composition rhaponiticin from counterfeit Rheum palmatum in Compound gentian and sodium bicarbonate tablets. METHODS： Totally 45 batches of Compound gentian and sodium bicarbonate tablets were collected from 8 domestic pharmaceutical manufacurers （No. A-H） in the field of drug distribution. TLC method was used to identify rhaponiticin in the samples primarily. The content of rhaponiticin was determined by HPLC， and then UPLC-MS/MS method was used to confirm the structure of rhaponiticin. RESULTS： TLC results showed that bright blue fluorescent spots of rhaponiticin could be seen in 10 batches of samples from manufacturer D at 365 nm wavelength of ultraviolet lamp. Results of HPLC methodology investigation showed that the linear range of  rhaponiticin was 0.884-88.4 μg/mL（r＝0.999 9）； the detection limit and quantitative limit were 0.707 2， 3.536 ng； RSDs of precision， reproducibility and stability tests were all lower than 1％； average recovery was 96.55％ （RSD＝0.53％，n＝6）. The contents of rhaponiticin in 10 batches of samples from manufacturer D were 0.732 4-2.890 8 mg/g. Results of UPLC-MS/MS method showed that quasimolecular ions with m/z of 419.0 and fragment ions with m/z 257.1 and 241.2 were found in both samples from manufacturer D and rhaponiticin control. CONCLUSIONS： TLC for primary screening， HPLC for content determination and UPLC-MS/MS for structure confirmation is simple， sensitive and reliable， and can be used for qualitative screening and quantitative determination of rhaponiticin in Compound gentian and sodium bicarbonate tablets. Among 45 batches of samples tested， rhaponiticin is detected in 10 batches of samples from one manufacturer， suggesting that the manufacturer substitute fake R. palmatum for genuine ones in the production of Compound gentian sodium bicarbonate tablets.