Abstract: A UPLC-Q-Orbitrap-MS based metabolomic approach combined with biochemical assay and histopathological inspection were employed to study the intervention effects of Suanzaoren Decoction (SZRD) on chronic unpredictable mild stress (CUMS) depression rats, and to clarify the metabolic regulation pathway of SZRD. The rats were randomly divided into normal control group, CUMS model group, positive drug venlafaxine group, SZRD high (24 g·kg^-1) and low (12 g·kg^-1) dose groups, respectively. The CUMS model was replicated by subjecting to a variety of stimulus, such as thermal stimulation, ice water swimming, ultrasonic stimulation, tail clamping, day and night reversal, plantar electric shock and so on for rats. After oral administration of drugs for 28 days, the behavioral indexes of rats in each group were observed and the hippocampus and serum samples of rats were collected for biochemical assay and histopathological inspection. Compared with the CUMS model group, low dose and high dose SZRD groups can significantly reduce the immobility time of forced swimming (P < 0.001, P < 0.001), increase the sucrose preference rate (P < 0.01, P < 0.05), the number of crossings (P < 0.05, P < 0.01) and the number of uprights (P < 0.05, P < 0.01) in the open field test, suggesting that SZRD can significantly improve the depression-like behavior of CUMS model rats. In addition, SZRD could significantly reduce the levels of serum IL-6, IL-1β and TNF-α of CUMS model rats. A total of 21 differential metabolites in serum were identified by comparison with the data from the literature and databases. In addition, low-dose SZRD and high-dose SZRD improved the 8 and 11 perturbed potential serum biomarkers that were induced by CUMS, respectively, which related to alanine, aspartic acid and glutamic acid, tryptophan and arachidonic acid metabolism. This study provides a scientific basis for expanding the clinical indications of SZRD. This experiment was approved by the Animal Ethics Committee of Shanxi University (Approval No. SXULL2020028).