This is normal, just monitor that he doesn't hurt himself. Also, look at the action leading up to your son's behavior. Like, did you give him a warning first and then say "no." What was he doing at that time?
I've been teaching my son since he was very young that feelings are okay. You know how some parents say "Don't be mad." Well, I tell my son that it's okay to be mad and then offer suggestions, give boundaries, etc. as to how "mad" manifests itself. So, it's okay to be mad, not okay to hit or throw. When he would cry, I would tell him to "breath in and breath out" and count to ten. And I would do it with him. So, now the tantrums are brief and he calms himself down fairly quickly. Plus, he can tell me how he feels- if he's mad or frustrated or tired.
This whole idea of validating feelings is important. We don't want our kids to grow up and second-guess their feelings, and we do want them to be responsible and choose good actions. It's like when I argue with my husband, sometimes I just want him to say to me "Honey, I hear you and I get how you feel." When he does this, I find myself calming down because I just wanted to be understood. Same thing with our kids.
Continue to give your son boundaries AND the vocabulary with which to express himself now and later in life. Good luck!
Take Care,
F.
www.discoverytoyslink.com/fatimac
(We have a wonderful teaching rhyming picture storybook called "THE WAY I FEEL" on sale now for only $9.99)