There are more than 30 known blood group systems recognized by the International Society for Blood Transfusion, including ABO, Rh, MN and P. The most important medical significance is that there are two blood group systems, ABO and Rh. The ABO blood group system has A and B antigens, and the Rh blood group system also has an antigen called Rh agglutinin, which is an antigen, and there is an anti-Rh agglutinin antibody in the serum. If the human blood type can produce agglutination with anti-Rh agglutinin antibodies, it is considered Rh-positive, while the opposite is not Rh-negative. However, the proportion of Rh negative in foreign white people is very high, accounting for about 15%, and the proportion of Rh in some of China’s ethnic minorities is also very high. The blood donated is basically Rh-positive, and the Rh-negative population is small and the number of donors is also small, commonly known as panda blood. The blood transfusion department should contact the blood center to recruit Rh-negative blood donors. If you know you have Rh-negative blood, contact the relevant department, such as the transfusion department, as soon as possible, or take the initiative to inform the doctors and nurses in the hospital to provide Rh-negative blood products in a timely manner.