My boyfriend always ask me of my past sexual intercourse life. Is this normal, and why would he want to know?

Normally, it is because they are insecure, if this is the case, do not answer the questions. There is no reason to share your past encounters, tell him that you are with him now, and that there is nothing else that you may want.

As to what men think, it depends on the man, and it depends on the woman.

How long have you been together, and how old are you? If one or both of you has insecurities, or trust issues, then small things like a roving eye and past relations will cause many arguments. So I guess it depends on the rest of the details of this relationship for a fair answer.

Maybe he wants to know how sexual you are,or he's trying to find out if your kinky..