The development of neuroimaging methods has enabled significant advances toward elucidating the mechanism of cognition, behavior and emotion. This article first reviews recent human neuroimaging studies that examined the neurocircuitry of emotion and emotion regulation. Next, we review the neuroimaging literature of the effects of cognitive behavioral therapy for depression. Lastly, we provide the brain mechanism that the emotional support regulates psychological pain in ostracism, and then discuss a biological model of psychotherapy. We hope that the present review can help us, not only to better understand the biological basis of cognition, behavior and emotion in psychotherapy, but also to be aware of effects of psychotherapy on brain.