The temporal bone in infants, especially the inner ear is the interesting structures, since it has some components that are growing rapidly and others have reached almost adult size. As there is almost no aeration of the mastoid, nor has the mastoid process as yet developed at birth this combination with the adult size development of inner ear structures and ossicles markes these portions of the petrous bone easily seen on routine skull views. It is our attempt to observe the inner ear structures of infants and measure the each inner ear structures, such as semicircular canals, cochlea and vestibule as base line and to detect any early anomaly of foregoing studies. Results as follow: 1. It is possible to measure the each inner ear structures in plain AP skull views. 2. There was no differences in size of vestibular length and width as comparing neonate and 1 year of age, however, there is slight enlargement of semicircular canals and cochlea as 1.4mm and 0.4mm, respectively. 3 It seems to be helpful to detect any early anomalous lesion of inner ear structure as basis of each measurement of these structures.