The work aims to establish a quantitative method for detecting bisphenol A in barrelled drinking water and to investigate the pollution level of bisphenol A in barrelled drinking water products sold in Beijing market. After sample pretreatment by a solid phase extraction method, bisphenol A was detected by liquid chromatography-tandem mass spectrometry. Under the optimal mass spectrum conditions for bisphenol A detection, the linear regression equation of level 1 mass spectrometry was y=69.4x+2186.1 with the correlation coefficient of 0.993 within the concentration range of 122.9~1190.7 ng/L. The limit of detection was 7.0 ng/L, and the limit of quantitation was 23.5 ng/L. The recoveries were between 78.8% and 108.1%, and the relative standard deviations (n=6) were less than 13.5%. Among 53 barrelled drinking water products from 6 water stations in Beijing, bisphenol A was detected in 36 products, but the concentrations were all lower than 0.01 mg/L that was the concentration limit required in Standards for Drinking Water Quality (GB 5749—2006). Owing to the advantages of excellent selectivity, high sensitivity and good reproducibility, this method can meet the detection demands of bisphenol A in barrelled drinking water. Bisphenol A widely exists in barrelled drinking water products sold in Beijing market, and long-term drinking thus leads to health risks.