5 year son with temper tantrums in school

My son has temper tantrums in school, sometimes to the pointe where he is kicked out of school. I don't what triggers these tantrums. My son is very smart he understands what you are saying.
My problem with him is he doesn't listen sometimes.
Please help what should I do?

[specialmom]

Has your son had tantrums at school before (preschool)?  Does he have tantrums at home?  Is this his temperment or a completly new behavior?  

My suggestion would be to volunteer in his class a few times and observe.  See what you yourself think may be going on.  You may see a trigger that the teachers don't.  In the meantime, ask his teacher to write down what proceeded the tantrum and then talk to your child about it.  Also talk to your son about appropriate ways to show frustration or anger at school.  He could go to a quiet corner in the room, he could deep breath for a count of ten, he could use his words and try to verbalize to the teacher what is wrong.  Give him the words to start this if he has trouble.  

Kindergarten is a notoriously hard time for little guys and gals as it is the first experience in which there are real expectations of them.  It can be a hard adjustment.  Volunteering and observing would really help you understand what is going on.  Try not to discipline him for it at home-----  but be empathetic and try to talk about it.  That way you get to the bottom of the problem vs. just making him feel worse.  Good luck.