Objective: To investigate the effects of Pinggan Prescription(平肝方, PGP) on hypertension by the associated methods of metabonomic and pharmacodynamic. Methods: A total of 32 male spontaneously hypertensive rats(SHRs) were randomly divided into two groups by using the random number table method:a treatment group(n=18) and a model group(n=14). The Wistar rats(n=14) were used as the normal group.Different prescription were used to intervene three groups: the treatment group in which PGP extract was administered orally at a dose of 18.336 g/kg(PGP/body weight), and the model group in which physiological saline was administered at the equivalent dose. The same treatment was applied to the normal group as the model group. The blood pressure was measured by tail-cuff method, and pharmacodynamic indexes including cyclic adenosine monophosphate(c AMP) and angiotensinⅡ(Ang Ⅱ) were tested by enzyme-linked immunosorbent assay. The plasma samples from three groups were detected by gas chromatography-mass spectrometry(GC-MS). Results: Compared with the model group, blood pressure of treatment group was obviously reduced after continuous curing with PGP(P<0.01). The pharmacodynamic results illustrated that the content of Ang Ⅱincreased with the raised blood pressure and the c AMP expressed the converse trend. After curing with PGP, the content of Ang Ⅱ decreased, the difference between model group and treatment group was signi?cant(P<0.01),and the c AMP expressed the converse trend. Five potential biomarkers were identi?ed, including arachidonic acid,hexadecanoic acid, elaidic acid, octadecanedioic acid and 9,12-octadecadienoic acid. These metabolites had shown signi?cantly changes as followed: arachidonic acid, hexadecanoic acid and elaidic acid were signi?cantly higher and octadecanedioic acid and 9,12-octadecadienoic acid were lowered in the model group than those in the normal group. After the treatment of PGP, the metabolites had the trends of returning to normal along with the reduced blood pressure. Conclusi