How can I help my boyfriends anger?

My boyfriend gets really angry sometimes to the point where he scares me. But he doesn't realize it at the time. I want to help him because I feel like it's taring the relationship apart sometimes, because he gets so angry at the smallest of things and when I try to help him he just gets angrier. It's upsetting me (he knows how I feel about it but he says he can't help it and if he could change it he would) but I love him and I want to help him...