Aim To study the pharmacodynamics of antianxietic compound prescription capsule ( ACPC ) on acute stress in rats and the influence upon the ex-pression of ERK/CREB signal pathway and brain-de-rived neurotrophic factor ( BDNF) in the cerebral cor-tex and hippocampus of rats. Methods The elevated plus maze ( EPM ) test was applied to observe the effects of ACPC on acute stress rats administered 7 d low-, medium- and high-dose ( 0. 75 , 1. 5 , 3 g · kg-1 ) . The expression of ERK/CREB signal pathway and BDNF in the cerebral cortex and hippocampus of rats were studied by using Western blot method. Re-sults In EPM, high-dose of ACPC increased signifi-cantly the rat open arm time ( OT%) ( P<0 . 05 ) and the percentage of open arm entries ( OE%) ( P <0. 05). In Western blot, the medium-dose of ACPC reduced significantly p-ERK1/2 expression in hippo-campus ( P <0. 05 ) , and high-dose group decreased significantly the expression of p-ERK1/2 and p-CREB in the cortex and hippocampus of rats ( P <0. 05 ) . High-dose group increased significantly the expression of BDNF in the cortex and hippocampus of rats ( P<0. 05 , P<0. 01 ) . Conclusion ACPC has anti-anxie-ty effect in the model of EPM, and its mechanism may be related to the ERK/CREB signal pathway and in-creased BDNF expression.