Transorbital ultrasonic examination was deviced by the anthor. The echo from the IVth ventricle were obtained by using this method. In order to record normal echo-gram, the probe (1MC or 2.25MC) was placed directly on the upper eyelid and the echos from the orbit, pyramid, IVth ventricle and occipital bone were recorded by this method. Clinically, this method would be applied to diagnosis of the infratentorial tumors. Abnormal echos would be obtained between the echos from the pyramid and the occipital bone on the side of tumor or the echo of the displaced IVth ventricle would be obtained.