How much will my dog's personality change?

I have a 7 month old boxer male, he is my first male dog and he has not been neutered as I have registered as a breeder for when he is old enough to breed, and i wish to do this responsibly. I show him locally, and he has the most outstanding personality. He has to be with you everywhere you go, he doesn't bark or dig or try to escape. He loves playing with kids and other puppies and dogs and knows how rough or gentle he has to be. I'm now wondering how much will his personality change as he matures???How much will my dog's personality change?
It sounds like you have given him a wonderful start, and he should only become more companionable as he ages. He may go thru some obstinate phases (note that most dogs in shelters are 8-18months of age), but if you just keep consistent, he should be fine.

Also, he will have a thing for the ladies (dog-ladies, that is), where he will become single minded in his obsession, to the exclusion of you (i.e.don't expect him to come when called if a female in season is within a mile).

Other than that, though, he sounds outstanding!How much will my dog's personality change?
not much the only thing that would change is as it matures an a female dog comes by keep an eye on that dog an dont let it play with one or u will have lil pupeys on ur hands haha unless u want some but yea he'll stay the same
If he's already as smart as you say, he should only become smarter as he gets older. He sounds like a great dog. He might not have as much puppy energy, but that should be it.
7 months old and you don't plan to neuter? As long as that dog is alive and confined to a yard with a 6 foot fence, (not chain link because Boxers can climb,) and is ALWAYS on the leash while outside, thing will be great! But I wish you great luck with that. It's this sex thing that will make his personality change and How it will change will depend a lot upon the trainer. If I could pass a Law, it would be that you can't be a breeder UNLESS you are certified as a Trainer! That would stop most puppy-mills in their tracks. OK, getting off the soap box. When a fem of any breed starts giving off those pheromones, he is not going to care what breed she is. It takes less than a few seconds for the puppy bomb fuse to be lit. BUT, if you take the time to train your dog the proper commands and he knows that YOU are Alpha, you will have a much easier time giving the Sit, Stay, and Down commands and being reasonably assured that he's going to think more of your alpha status than running off for a trick with that cute terrier. Undoubtedly, his performance in the show ring will be affected as he gets older. The website below can help with more information.
He won't change too much. He should get a little more reserved and may be a bit less playful with others. Keep him away from any b****es in heat or he could start challenging other males.