The ratio of chest compressions to artificial respiration in resuscitating an adult is 30:2. Adults experiencing respiratory arrest need immediate CPR, and the ratio of chest compressions to respiration in adult CPR is 30:2. The frequency of chest compressions should be 100-120 times per minute, and the depth of compressions should be about 5-6 centimeters in order to achieve the effect of effective compressions. The position of compression is the midpoint of the line between the two nipples. When you find someone collapsed, you need to first assess the safety of the surrounding environment, and then determine the patient’s condition such as call for no response, no spontaneous breathing, can not touch the carotid artery pulsation, you need to immediately start CPR, and call for help, so that people around you to call the 120. in the 120 before the arrival of the least possible interruption of the compression. The above operations are recommended to be performed by people with a medical background, so as to avoid the failure of resuscitation or the triggering of new complications.