Objective：To investigate the reversal effect of the effective component of Verbena Officinalis L. （4’-methery-scutellarein,4’-M-S） on multidrug resistant JAR／VP16 cell line. Methods：MTT［3-（4，5-dimethylthiazol-2-yl） 2，5-dipheny tetrasodium bromide］ assay was used to examine the action of 4’-M-S on proliferation of JAR／VP16 cells, determine the available reversal concentration of 4’-M-S and measure the reversal index and ratio on JAR／VP16 cells. Secretory volume of chorionic gonadotrophic hormone（hCG） was measured by monoclonal antibody enzyme-linked immunoquantitation. Cell cycle profile and apoptotic cell rate was examined by flow cytometry（FCM）, the morphologic and ultramicrostructural changes were observed with light and transmission electron-microscope（TEM）. Results：The resistance of JAR／VP16 to VP16, MTX and ACTD, was enhanced up to 5.02，3.67，2.48 folds and ratios of 81.19%，76.89%，64.08% after exposure of the cells to 20 -滋g／ml 4’-M-S, respectively. Secretory volume of hCG in drug-resistance cell was decreased obviously when treated with combination of 4’-M-S and VP16. Cell cycle was blocked at the period of G0-G1 and G2-M , cell apoptotic rate was increased to 19.71%. The earlier apoptotic changes were observed under TEM in the cells treated. Conclusion:4’-M-S has a strong reversal effect on multidrug resistance in JAR／VP16 cells, which may be achieved by inhibiting growth of JAR／VP16 cells and inducing cell apoptosis.