Medical rescue is the most important step in the rescue action during grave disasters. Prompt and effective medical intervention is the key to decrease the death and disable rates in the salvage of the wounded. The authors participated in the medical rescue after China Wenchuan earthquake. Ultrasonography discovered the symptoms such as pleural effusion,pyoperitoneum,hepatic rupture,cystorrhexis,and so on,which contributed to the quick and accurate classification of patients. More emphasis should be given to ultrasonography examination during the on-spot medical rescue action after grave disasters,so as to timely differentiate patients and allow them to have timely and proper treatment,which can not only save time,but also improve the rescue efficiency.