Contents: -- Introduction to Critical Ultrasound in Pediatric Pulmonaly & Critical Care -- Basic and Principle of Ultrasound -- Lung Ultrasound: Basic physics and practical point for critically ill patient -- Abdominal Ultrasound in Critical Care -- Ultrasound Guided Vascular Access -- Basic Transthoracic Echocardiography in Critically-ill Children -- Noninvasive Cardiac Output Monitoring in Pediatrics -- Reporting Guideline for the Focused Assessment with Sonography for Trauma (FAST) Examination