RH positive means that a person’s RH blood type is RH positive, because in addition to the human blood type ABO blood type, there are many other blood types, among which the closely related in the clinic is the RH blood type. RH blood type was first discovered from the red blood cell membrane of Indian rhesus monkeys, according to whether the red blood cell membrane contains D antigen, RH blood type is divided into positive and negative, containing D antigen is RH positive, and those without D antigen is RH negative. Those that contain D antigen are RH positive, while those that do not contain D antigen are RH negative. In China’s Han population, RH-positive people account for the majority and RH-negative people are very rare. RH-negative people can only receive RH-negative blood during blood transfusions, while RH-positive people can receive both RH-positive and RH-negative blood.