Brenda: I'm not trying to be smart, but without more information, your post is about as good as opening your front door and yelling out of it.
Who is this man? What was his military branch ( army, navy, air force) ? In which county's military did he serve? ( Canada, UK USA) What do you wish to learn about him? What is your relation to him?
What information do you have now? I maybe able to help you, but you will have to provide more details. Military records for Canada are quite good, but you have to have certain basic facts to work with, such as his service number and branch od service. His date of birth, the full and correct spelling of his name, and the time/date he enlisted, are all helpful.
I served 30 years in the Canadian Army, from 1966 to 1996, so I have some connections to help you , no charge. Please advise me of any more details you have re him. Jim Bunting, toronto.