Platelets are also divided into blood groups. The blood group systems commonly used in clinical practice are the ABO blood group system and the Rh blood group system, and the determination of the blood group system is very important for clinical transfusion. In addition to red blood cells, platelets are also typed. In clinical practice, for patients with significantly lower platelets and bleeding, platelets need to be transfused, and in general, homotypic transfusion is required. For example, O- and Rh-positive patients must be transfused with O- and Rh-positive platelets. However, there are special cases, if the platelets are Rh-negative, the patient can also be transfused with Rh-positive platelets during emergency resuscitation, because the platelets contain almost few red blood cells, so the platelet Rh blood type is not considered in emergency situations.