This study amis to compare the changes in the major active constituents of Bupleurum Radix-Paeoniae Radix Alba (BR-PR)single flavor,drug-pair formula granules and traditional decoction using high performance liquid chromatography (HPLC).The difference in antidepressant effects between the combined decoction and single decoction of drug pairs was investigated using a model of acute depression antagonised by reserpine.A COSMOSIL 5C₁₈-MS-II column (250 mm×4.6 mm,5 μm) was used;acetonitrile (A)-0.1% phosphoric acid solution (B) was used as the mobile phase;the volume flow rate was 1.0 mL/min;The column temperature was 30 ℃;the injection volume was 10 μL;and the detection was carried out at dual wavelengths (210 and 230 nm).The effects of different dosage forms on depression in mice were analyzed by enzyme linked immunosorbent assay kit and HE and Nissl staining.The contents of saikosaponin a,saikosaponin d,paeoniflorin,paeoniflorin oxide in BR-PR single flavor formula granules mixed solution were lower than BR-PR drug-pair formula granules and traditional decoction.The levels of 5-hydroxytryptamine and dopamine (P<0.05,P<0.01) were significantly increased in the BR-PR single flavor formula granules mixed solution group,BR-PR drug-pair formula granules group,and traditional decoction group;The contents of interleukin-6,interleukin-1β and tumor necrosis factor-α in serum significantly decreased (P<0.05,P<0.01),the anti-inflammatory factor interleukin-10 was significantly increased (P<0.05,P<0.01);The superoxide dismutase was increased,while malondialdehyde significantly decreased in liver tissues (P<0.05,P<0.01).HPLC method has good repeatability,stability and reliability.By inhibiting inflammation and relieving oxidative stress,BR-PR drug-pair formula granules and traditional decoction improved depressive symptoms significantly than BR-PR single flavor formula granules mixed solution.