Regular respiration is an important parameter of quiet sleep in infants. At the earliest age, the periods of regular respiration are shorter as compared with the periods of EEG, EMG and EOG patterns of quiet sleep. The duration of periods with regular respiration significantly increases with age, and their coincidence with other parameters of quiet sleep becomes higher. The frequency of regular respiration significantly decreases with age. Very short periods of regular respiration, low coincidence with other parameters of quiet sleep, and very high frequency of regular respiration after the 12th week of life may indicate a delay in the central nervous system development.