Blood type B is one of the ABO blood group systems. Blood type B refers to a person who has B antigens on the surface of red blood cells, and the serum produces antibodies against A antigens, but not B antigens. 1. The ABO blood grouping system is the most commonly used for classifying human blood. The ABO blood grouping system classifies blood into four blood groups based on the presence or absence of certain heritable antigenic substances on the surface of red blood cells: A, B, AB and O. The ABO blood grouping system is based on the presence or absence of certain heritable antigenic substances on the surface of red blood cells, which are classified into four blood groups. 2. Type B blood refers to the presence of B antigens on the surface of the red blood cells, and there will be antibodies against A antigens and no antibodies against B antigens in the serum, which is the opposite of people with type A blood. 3. People with blood type B can receive blood type B or O, but in principle, blood transfusion should be done with blood of the same type to avoid the occurrence of hemolytic anemia, which is life-threatening.