To check your blood type you need to have blood drawn from a vein for testing. There is no need to fast for the blood test and blood can be drawn at any time of the day. 1. If you don’t know what your blood type is and at the same time want to find out your blood type, you can go to the internal medicine department of a hospital, explain your purpose to the doctor, who will issue an application form, and you can take the application form to the Laboratory Department for a laboratory test. By taking peripheral blood, the blood type examination is conducted, and the result of the blood type can usually be tested in about 20 minutes. 2. The ABO blood group system and Rh blood group system are common in clinical practice. The ABO blood group system includes type A, B, AB and O; the Rh blood group system, refers to Rh-positive and Rh-negative. Generally speaking, there is no difference between good and bad blood types, but the distribution of blood types in the population may vary, for example, the distribution of Rh-negative blood in the Chinese population is relatively low. 3. Blood type is determined by testing for blood group antigens on the red blood cells in the blood, and blood group antibodies in the plasma to determine the patient’s blood type.