If someone goes into cardiac or respiratory arrest outside of a hospital, CPR needs to be given. The ratio of CPR compressions to blowing is 30:2, the specific practice is to open the airway, mouth-to-mouth artificial respiration and chest compressions. The part of the chest compression is the middle of the level of the line between the two breasts, the root of the palm of the hand to overlap with the same phase, ten fingers interlocked palms close to the chest wall, the fingers should try to leave the chest wall, the two upper arm type straight, the upper half of the body leaning forward. Take the hip joint as the fulcrum vertical downward, hard rhythmic pressure 100-120 times / min, the ratio of pressure and ventilation is 30:2, do five cycles and then observe the breathing and pulse is not restored.