A blood type RH positive is a description of a person’s blood type, that is, the person is type A in the ABO blood type system and belongs to RH positive in the RH blood type system. The ABO blood group system is relatively well understood by the general population and is divided into A blood type, B blood type, AB blood type and O blood type. However, the RH blood group system is relatively unknown to the general public. The RH blood group system was first discovered on the red blood cell membranes of Indian rhesus monkeys and is divided into RH positive and RH negative according to whether the red blood cell membranes contain the D antigen, and those containing the D antigen are RH positive and those not containing the D antigen are RH negative. So A blood type RH positive means A blood type in the ABO blood group system and RH positive blood in the RH blood group system.