Assuming you already know your blood type (otherwise see: Blood type dating: Who is perfect for you?), go here:
https://www.datebytype.com/users
Mark that you are looking for a partner who shares your blood type and see if there is someone interesting. If not, use the following formula:
If you are a woman, find a man who can donate blood to you. If you are a man, find a woman you can donate blood to.
