A method was developed for the simultaneous determination of flavanols,isoflavones,flavonols,dihydroflavones,flavanonols,chalcones,pterocarpan,anthocyanidins and phenolic acids in Spatholobi Caulis with different phloem ring numbers by ultra fast liquid chromatography coupled with triple quadrupole/linear ion trap tandem mass spectrometry(UFLC-QTRAP-MS/MS).The quality of Spatholobi Caulis with different phloem rings was analyzed and evaluated.The analytes were separated on an XBridgeC18 column(4.6 mm×100 mm,3.5 μm) at 30 ℃,with 0.3% formic acid aqueous solution-methanol as mobile phase by gradient elution at a flow rate of 0.8 mL·min-1,and detected in multi-reaction monitoring(MRM) mode.According to the contents of 22 target components,88 batches of Spatholobi Caulis from three regions with different phloem rings were evaluated by principal component analysis(PCA).Results showed that there were good linear relationships for 22 target components in the tested concentration range with correlation coefficients(r) not less than 0.999 0.The limits of detection(LOD) and limits of quantitation(LOQ) were in the ranges of 0.07-7.99 ng·mL-1 and 0.22-26.63 ng·mL-1,respectively.The average recoveries for the 22 components ranged from 96.8% to 103% with relative standard deviations of 0.80%-4.4%.There existed a positive correlation between the number of phloem rings and the content of multiple index components.The contents of the index components in Spatholobi Caulis from three production areas of Gaoyao,Vietnam and Laos were higher with 10 rings,8 rings and 9 rings,respectively.PCA analysis showed that the samples provided by Gaoyao with 10 and 9 rings had better comprehensive quality.In this paper,the correlation between phloem ring numbers and the content of index components in Spatholobi Caulis was established to provide a scientific basis for evaluating the quality of Spatholobi Caulis based on its characteristics.It also provided a new idea or method to clarify the scientific connotation of traditional experience essence of traditional Chinese medicine.