Abstract: Dorsomedial hypothalamic nucleus (DMH) is an important component of autonomic nervous system, which has extensive connections with limbic system. DMH may participates in the regulation of negative emotions, such as anxiety and fear. However, the cellular mechanisms are still unknown. In this study, elevated plus maze and open filed tests were performed, and a bidirectional effect of optogenetic modulation on behaviors was found. Activating the DMH glutamatergic or gamma-aminobutyric acid (GABAergic) neurons leading to the anxiety-like behavior and increasing of heart rate, while optical inhibition significantly suppressed the anxiety-like behavior and decreased heart rate. These findings may provide new targets for clinical therapy for neuropsychiatric disorders.