To understand and explore the functional nutrients in Nasturtium officinale R.Br.,an ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established for the qualitative and quantitative analysis of 17 phenolic acids in 18 N. officinale cultivars.The optimal detection method obtained by optimizing the parameters of UPLC-MS/MS condition was as follows:the samples were separated using an HSS T3 column and eluted with 0.1% formic acid-acetonitrile as mobile phase,the flow rate was set to 0.3 mL/min and the column temperature was set to 30℃.A total of 17 phenolic acids in N. officinale were detected by negative ion mode scanning.The separation effect of compounds is good.The linear ranges of 17 phenolic acids showed good linearity (R ≥ 0.999 2),the limit of detection ranged from 0.8401 μg/mL to 4.040 μg/mL,the limit of quantitation ranged from 2.001 μg/mL to 20.50 μg/mL,and the average recovery ranged from 94.63% to 102.4%,relative standard deviation≤4.4% (n = 6).All 17 phenolic acids in 18 N. officinale detected by our method were quantitatively measurable.The total phenolic acid content in different cultivars and the accumulation of 17 kinds of phenolic acids in the same N. officinale cultivar were significantly different.The total content of phenolic acids ranged from 106.0 mg/g DW to 230.0 mg/g DW.Among them,p-hydroxybenzoic acid,ellagic acid,chlorogenic acid and 3,5-dihydroxybenzoic acid were the main phenolic acids in N. officinale.In summary,the UPLC-MS/MS method can quickly and accurately analyze the composition and distribution of phenolic acid compounds in N. officinale,and establish a technical platform for the subsequent mining of excellent phenolic acid-rich germplasm resources of N. officinale,which is helpful to accelerate the improvement of N. officinale cultivars.