Anger has many hidden reasons. You need to work on it. Following questions, you need to answer for finding out the solution.
1. Is he getting angry with every one?
2. Is he short tempered by nature?
3. Is he frustrated on any front like work, money, relationship etc?
4. Does anger runs in the family?
These are some of the basic questions, which will help you to identify cause of anger and then you deal with it accordingly. You may require professional intervention if things are not possible to worked out at your end.