Wet rales, i.e. blister sounds, are produced by the rupture of the blisters formed by the passage of gas through the liquid during respiration due to the presence of thin liquids in the trachea or bronchi, such as exudate, sputum, blood, mucus, pus sputum, etc. It is mostly seen during inspiration, or more clearly at the end of inspiration, and sometimes also in early expiration, with a more constant location and nature. Due to the large diameter of the diseased bronchial lumen, or the size of the cavity is different, the amount of liquid is different, the sound of wet rales have coarse, medium, fine different or called large, medium, small alveolar sound, inspiration at the bottom of the lung airless area to help first close the small airway alveoli suddenly open can produce “inspiratory burst sound”. 1, auscultation examination ① inspiration and expiration can be heard, to the end of inspiration more and clear, because the inspiratory airflow speed is faster and stronger, the end of inspiration bubble large, easy to rupture; ② site more constant, the nature is not easy to change. 2, the clinical significance of wet rales is the lung and bronchial lesion performance. Wet rales are scattered in both lungs, commonly found in bronchitis, bronchopneumonia, hematogenous tuberculosis, pulmonary edema; distributed at the base of both lungs, mostly seen in pulmonary stasis, pulmonary edema and bronchopneumonia; distributed on one side or limited, commonly found in pneumonia, tuberculosis (mostly in the upper lung), bronchiectasis (mostly in the lower lung), lung abscess, lung cancer and pulmonary hemorrhage, etc.