Background. Preliminary research showed that linarin (LIN) might have a relationship with the antihypertensive effect of Dendranthema indicum flowers. However, the preparative method for LIN enriched extract from Dendranthema indicum flowers was not clear and its antihypertensive effect was not confirmed. In this study, we designed a series of experiments to develop an efficient method for purification of LIN extracts and confirm the possibility of LIN extracts to be an antihypertensive drug. Materials and Methods. HPLC-VWD/DAD were used in the process of developing purification method. The antihypertensive effect of LIN extracts was tested by CODA Mouse & Rat Tail-Cuff Blood Pressure System; western blot and biochemical analysis were used to investigate mechanism and toxicity. Results. The content and recovery of LIN reached 55.68 ± 2.08% and 66.65 ± 1.73%, respectively, through solid-liquid extraction. The composition of product was stable through the analysis of fingerprint. Chronic administration of LIN extracts reduced blood pressure obviously which had a relationship with the inhibition of renin-angiotensin system (RAS) in kidney and the function indexes of kidney and liver had no variations. Conclusions. The preparation method was simple, low-cost, and stable, and it was fit for industrial application. The LIN prepared by this method had the potential to be an antihypertensive drug.