Abstract: This study is to investigate the sedative and hypnotic effects of a novel compound H1208.The sedative activity of H1208 was investigated by recording the spontaneous locomotor activity of mice.Thehypnotic property was evaluated by the latency and duration of sleep (loss of righting reflex) in mice and the effect of hypnotics on sleep pattern of electroencephalogram were studied in conscious, freely moving mice with chronically implanted electrodes.The brain monoamine neurotransmitters levels in mice were measured by high performance liquid chromatography-electrochemical detection.The spontaneous locomotor activity was decreased by 56.7% and 80.2% in H1208 (5 and 25 mg·kg^-1, ip) treated mice, respectively.The loss of righting reflex was directly induced in mice after H1208 (60 mg·kg^-1, ip) administration.The non-rapid eye movement sleep increased significantly by 131% and 259%, respectively, within 3 hours after H1208 (30 and 60 mg·kg^-1,ip) administration.However, the rapid eye movement sleep decreased significantly.The contents of DA in the striatum and cortex and 5-HT in the cortex decreased significantly.These results demonstrated that H1208 has potent sedative and hypnotic effects, which may be closely related to the decreased contents of DA and 5-HT in mouse brain.