1. The relation between the response to photic stimulation and the photic driving was investigated on 25 students of our school.2. In the eye-closed state, simple sinusoidal waves of large amplitude were obtained by continuous rhythmic photic stimulation of a frequency equivalent to that of the alpha-like waves resulting from photic stimulation.3. Averaged waves of the EEG responses to the stimulation with frequencies lower than that of the alpha-like waves were composed of a few small characteristic waves. These small waves may be composed of the initial response and the rudiment of the alpha-like waves.4. With frequencies above that of the alpha-like waves the initial response only was observed in the averaged waves.5. In the eye-opened state an increase of the response amplitude to each photic stimulus in the train of stimulation at about 10 cps was not observed, while in the eye-closed state the response to each stimulus in a train of the same frequency stimulation augmented up to the 7th stimulus from the beginning of the train.6. In drowsy state photic driving of theta waves was not observed even at a frequency of stimulation within the theta wave range.7. Photic driving of alpha waves appears to be due to the summation of alpha-like waves resulting from each photic stimulus in the train of stimuli.