OBJECTIVE To establish a method for simultaneous determi nation of six components in Melastoma dodecandrum and investigate its correlation with antioxidant activity. METHODS Ultra high-performance liquid chromatography （UPLC）method was adopted. The contents of gallic acid ，protocatechuic acid ，isovitexin，rutin and ellagic acid in 23 batches of M. dodecandrum were determined by quantitative analysis of multi-components by single-marker （QAMS）method，using vitexin as the internal reference. Then 1，1-diphenyl-2-picrylhydrazyl（DPPH）free radical method ，2，2′-azino-bis（3-ethylbenzothiazoline-6-sulfonic acid ） diammonium salt （ABTS）method and ferric ion reduction/antioxidant power （FRAP）method were applied to determine the antioxidant activity of 23 batches of M. dodecandrum . Grey correlation analysis and bivariate correlation analysis were used to evaluate the correlation between six components and antioxidant activity. RESULTS The content of vitexin were 0.021％-0.182％. The contents of gallic acid ，protocatechuic acid ，isovitexin，rutin and ellagic acid by QAMS method were 0.008％-0.042％， 0.003％-0.023％，0.071％-0.283％，0.013％-0.140％ and 0.006％-0.021％，respectively. Compared with the results of external standard method ，P was greater than 0.05. Grey correlation analysis showed that the grey correlation coefficients between the contents of six components an d antioxidant activity was 0.727 6- 0.866 9. Bivariate correlation analysis showed that the contents of vitexin ，isovitexin and rutin were positively correlated with antioxidant activity （P＜0.05 or P＜0.01），the content of gallic acid and protocatechuic acid were negatively correlated with antioxidant activity （P＜0.05）. There was no significant correlation between ellagic acid and antioxidant activity.CONCLUSIONS QAMS method is successfully established for the simultaneous determination of six components in M. dodecandrum. The six components in M. dodecandrum are highly correlated with antioxidant activity.