Brain derived neurotrophic factor (BDNF) can prevent neurons from death, promote growth, development and differentiation of neurons, enhance restoration and regeneration of neurons, and reinforce signal transduction among synapses. It has been revealed that BDNF is related to the pathogenesis and treatment of bipolar disorder. The downstream signaling pathway of BDNF changes accordingly in bipolar disorder, and the mechanism of mood stabilizers in treatment of bipolar disorder may be related to the up-regulation of BDNF expression by mediating factors in the downstream signaling pathway of BDNF. In this paper, the relationship between the pathogenesis and treatment of bipolar disorder and signaling pathway of BDNF is reviewed.