Objective: To study the effect of Baihe Dihuang Decoction in improving anxiety and its mechanism of action. Methods: Male mice were randomly divided into 5 groups: blank control group, Baihe Dihuang Decoction high, medium, low-dose group and diazepam group. After continuous intragastric administration for 14 d, the behavioral test of the mouse elevated plus maze experiment and opening test was performed. The brain tissue GABA and Glu content was measured by immunosorbent assay (ELISA). Results: Compared with the blank control group, the middle and high doses of Baihe Dihuang Decoction could increase the time and frequency of movement of the mice in the open cross labyrinth in the open arm and increase the number of times that the mouse entered the central area in the opening test. The anti-anxiety effect also showed an increase in the brain tissue GABA content in mice, ignificantly decreased Glu contents in mice. Conclusion: Baihe Dihuang Decoction has some anxiolytic effect, and antianxiety effect may be related to increasing brain tissue GABA content, decreased Glu contents in mice.