During the Yushu Earthquake on April 14,2010,a high incidence of acute high altitude illness was observed in the mountain rescuers,and 0.73 % of these patients suffered from high altitude pulmonary edema,of which 12 patients developed subclinical pulmonary edema and concomitantly contracted acute mountain sickness. Symptoms and signs were atypically high heart rate with high respiratory rate,striking cyanosis,and significantly low oxygen saturation,whereas no moist rates were heard on auscultation,and Chest X-ray showed peripheral with a patchy distribution of mottled infiltrations in one or both lung fields. We believe that subclinical high altitude pulmonary edema is an earliest stage of pulmonary edema at high altitude. The possible pathogenesis and the diagnosis were discussed. During the Yushu Earthquake on April 14,2010, a high incidence of acute high altitude illness was observed in the mountain rescuers, and 0.73% of these patients suffered from high altitude pulmonary edema, of which 12 patients developed subclinical pulmonary edema and concomitantly contracted acute Mountain sickness. Symptoms and signs were atypically high heart rate with high respiratory rate, striking cyanosis, and significantly low oxygen saturation, and no moist rates were heard on auscultation, and Chest X-ray showed peripheral with a patchy distribution of mottled infiltrations in one We both believe that subclinical high altitude pulmonary edema is an earliest stage of pulmonary edema at high altitude. The possible pathogenesis and the diagnosis were discussed.