The aim of this study is to show the polysomnogram of hypnagogic period. Sixteen subjects slept for two nights. Their EEGs (Fz, Cz, Pz, Oz), horizontal and vertical EOGs, submentalis EMG, thoracic and abdominal respiration were recorded. They pressed a button when pip tones (1000Hz, 50dB, max duration : 5s, ISI : 30-90s) were presented, and reported their psychological experiences, According to Hori et al. (1994), the hypnagogic EEGs just 5s before the pip tones were classified into 9 stages, as follows; 1) alpha wave train, 2) alpha wave intermittnet (%α>50), 3) alpha wave intermittent (%α<50), 4) EEG flattening, 5) ripples, 6) vertex sharp wave solitary, 7) vertex sharp wave bursts, 8) vertex sharp wave and incomplete spindles, 9) spindles. The polysomnograms of these 9 EEG stages were presented. Physiological, behavioral and subjective changes were observed as a function of hypnagogic EEG stages.