Fruits of Fructus Schisandrae have been used as medicine for the treatment for insomnia in traditional Chinese medicine. In the present research, the sedative and hypnotic activities of the ethanol fraction of Fructus Schisandrae fruit (SY3) were studied in mice and rats. In the open field test, SY3 (25, 50 and 100 mg/kg) significantly inhibited the motor activity of mice compared to the normal. Results also showed SY3 potentiated pentobarbital-induced sleep by not only increasing the number of falling asleep and prolonging sleeping time but also reducing sleep latency. Furthermore, sleep-wake stages of rats were evaluated by polytrophic recording for 3 h after treatment. The results demonstrated that SY3 at doses of 20, 40 and 80 mg/kg behaved remarkable action on sleep architecture of rats, which contain the increase of total sleeping time, the rate of deep slow wave sleep (SWS) and mean episode duration of deep SWS, and the decrease of the latency of deep SWS. Therefore, these results suggest that the ethanol fraction of Fructus Schisandrae fruit possesses potent sedative and hypnotic activity, which supported its therapeutic use for insomnia.