Abstract:Objective: To screen the antidepressant fractions of Banxia Houpu Decoction. Method: Behavioral despair models in mice were used to evaluate antidepressant activities and the levels of monoamine neurotransmitters in regions of animal brains were determined with spectrophotofluoremetry method. Result: The extract of Banxia Houpu Decoction (AE) and its four fractions were able to elicit time-dependent reducing of duration of immobility in the tail suspension test and the forced swimming test in mice. A-mong these test samples, AE, petrol fraction (AE-1) and water soluble fraction (AE-4) were more potent, but there was no significant difference between them. AE significantly increased 5-HT level in mice striatum and NE level in mice cortex, respectively, and did not affect any monoamine neurotransmitters in other regions of animal brain. AE-1 elevated 5-HT level in the striatum and the NE and DA level in the cortex, chloroform fraction (AE-2) only significantly increased DA level in cortex. Conclusion: Banxia Houpu Decoction has antidepressant effect. The active parts are in AE-1 and AE-4. The antidepressant action of Banxia Houpu Decoction is probably be mediated in part through many monoamine neurotransmitter systems.