The aim of this study is to investigate the relationships between hypnagogic imagery and EEG stages. According to Hori, et al. (1994), the hypnagogic EEGs was classified into 9 stages, those were 1) alpha wave train, 2) alpha wave intermittent (>50%), 3) alpha wave intermittent (<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. EEGs (Fz, Cz, Oz) were recorded from light off to 90 min elapsed. The subjects pressed a button when pip tones (1000Hz, 50dB, max duration : 5s, ISI : 50-70s) were presented, and reported their psychological experiences. The results showed that reaction time prolonged with progress of the hypnagogic EEG stages. The hypnagogic imageries mostly experienced when theta waves or a vertex sharp wave occurred. These imageries were almost composed of visual imageries (88%), involved 1) persons (37%), 2) static objects (21%), 3) landscapes (10%), and 4) colored patterns (8%). These imageries changed from waking daydreams to hypnagogic imageries or NREM sleep dreams as a function of progress of hypnagogic EEG stages.