Objective: To detect the expression of γ-aminobutyric acid B receptor (GABABR)and adenylate cyclase (AC) of forbral cortex in rats with anxiety emotion and to explore the antianxiety mechanism of baixiangdan capsule. Method: Paeoniflorin

cyperolone and paeonolum were main ingredients of baixiangdan capsule. Wistar rats were divided into normal group

model group

baixiangdan capsule group(200 mg·kg-1) and baclofen group(8 mg·kg-1). The rats were administrated with relevant drugs intragastrically once a day for 7 days. The anxiety emotion rat models were established by a social isolation plus resident intruder stress. The rats were evaluated by sucrose intake

the open field and elevated plus-maze tests. The expression of GABABR1

GABABR2 and AC in frontal cortex were detected by the immunoflourescence. Result: Compared with normal group

the model group had the lower sucrose intake

the higher total score of open field tests

the lower open arm entry percent(OE%) and the lower open arm time percent (OT%) of elevated plus-maze tests and the lower expression of GABABR1

GABABR2 and AC in frontal cortex. Compared with model group

baixiangdan capsule and baclofen decreased the total score of open field tests

increased the OE%and OT%of elevated plus-maze tests and the expression of GABABR1

GABABR2 and AC in frontal cortex. Conclusion: The lower expression of GABABR1

GABABR2 and AC in frontal cortex may have close relationship with anxiety emotion. Increasing the expression and the function of GABABR in frontal cortex maybe one of the mechanisms of the antianxiety effect by Baixiangdan capsule.