2nd Version of: All about Rottweilers!!!

Changing behavior is all about controlling the environment to prevent the practice of unwanted behavior and specifically teaching new behaviors that you want.
 
Management could be to use drag lines in the house so you can control the dog when people come to the door or you want to move him some where he really does not want to go.  Management is using a muzzle while he learns self control.   Management is practicing commands at a distance where the dog can focus on you not something that is distracting.
 
One website that offers lots of information on training in general is  [linkhttp://www.hollysden.com/Basic-dog-and-puppy-training.htm]http://www.hollysden.com/Basic-dog-and-puppy-training.htm[/link]   Although this dog is an adult the training principles apply to any age.
 
Small training sessions of 10 minutes multiple times during the day are a better plan than one longer session.

You got a gaurd dog and he is doing his job.  He is protecing your house and family from all the other people and dogs out there who he thinks are a threat.  I'm guessing the problem is noone ever taught him about who is a threat and who isn't.  It's important to take dogs out as puppies around strange dogs and eople and teach them how to interact.  They will learn what is normal conversation between people and what could be a threat.  If they never learn what isn't a threat then they can't tell when someone or something is dangerous and could hurt you.  He's assuming everything and everyone is dangerous to you.  It's much harder to reteach them after that but not completely impossible.

First thing to do is some obedience.  Make sure he will walk next to you and sit to a command(it doesn't have to be in english).  If you don't know how to do that I highly suggest hiring a trainer and getting some books on basic obedience training.  When you've accomplished that make sure to have him on a strong leash and either be certain you can hold onto him and keep him in place or tie him to something.  Have someone he knows come into view and casually walk by a good distance away.  Not close enough that you would start a conversation with the person but just within view.  When he barks first try to tell him the person isn't dangerous and for a puppy I would even pet them a little but I'm not sure he really needs any such reassurance.  If he doesn't calm down a little then reprimand, tell him "NO, quiet", and make him stay next to you in a sit until the person walks out of sight.  Repeat until he starts to sit at least somewhat more quietly and make certain you praise him greatly for behaving.  Tell him how great he is for sitting there instead of jumping up and trying to bark at the person or even for just grumbling instead of all out barking loudly.  It may take doing this on a couple different days to make any progress. 

Next step is to have the person approach close enough you can start a conversation but not close enough they could easily make physical contact and potentially hurt you.  Greet the person in a friendly way, tell the dog it's ok and the person is not dangerous, and if the dog continues to get upset go back to making it sit and repeating the "NO, quiet" command or whatever word you decide to use to tell the dog not to bark anymore.  When the dog is sitting or after you have talked to the person for a couple minutes then have them walk away.  Do it again until the dog stays sitting and quiets a little when you tell it to. 

When the dog improves keep increasing the events.  Have the person walk up quicker or closer to you, get different people or people the dog doesn't know as well to approach you, and eventually have other owners bring their dogs by.  Always make sure you keep control of your dog and if you can't control him back off to a previous step where it was easier.  Like tying him to the fence and having someone just walk by across the street.  When you start having him around other dogs don't let them meet each other at first.  Keep the other dog at a distance until your dog is calm and slowly let them get closer.  Whenever he misbehaves reprimand him, make him go back to sitting next to you, and don't allow the other dog any closer until you have control of him.  Eventually he should come to learn when things are ok and when things are different which could mean a threat.  If someone yells at you instead of greeting politely or you get nervous and don't tell him it's ok then he will know that this is a bad situation because he has something to compare it to.  You can't expect him to be born knowing the difference between a safe human and a dangerous one.  You have to teach him how to tell the difference.

Lastly neutering this dog would help greatly.  With his personality you really shouldn't be creating any puppies.  They could be just as hard to handle as him.  It would also make him much easier to handle with neutering.  There are plenty of rottweilers out there to pass on their genes.  You shouldn't be breeding yours unless both he and the female you choose are absolutely perfect in every way.  You'd be better off concentrating on making him a safe happy pet and guardian for your family instead of trying to make more puppies.

Hello guys again, thank all og you for replying and giving your advices! But I need more people's advices..

I think about the only other advice you'll get is to hire a professional to work with him.  Few people want to try to work with a dog that has become that agressive.  Here he'd probably have been put down already for attacking people.  No place would likely even try to find him a home.  If you really want to keep him and everyone else safe you either need to confine him very well so he can't ever reach anyone or their dogs again or start working hard to socialize him and teach him some obedience so he's safer to be around.  Rotties can be very wonderful loving dogs to their family including other pets in the family but they need discipline and training or they can become a major handful and dangerous to people and animals outside your family.  My mom's rott was abused as a puppy and I spent a lot of time working with him before we could trust him around any people.  We still have to lock him in a bedroom occasionally when certain people he finds extra threatening come over.  It's not only for their safety but his since if someone reported a dog bite here they would take our dog and probably have him put down for being dangerous.

What a beautiful boy indeed!!!!
 
I know your looking for more advice but unfortunately, I cannot think of a single thing that  Sham did not already cover for you.
Patience and a lot of work with a trainer as well as the idea of a neuter were my thoughts as well. Best of luck, wish I could help.

Hello my friends, thank all of you! Your advices were very good, and I'm proud to have friends like you.. god bless all of you.. this is the end of this post.. thanks again for taking part good bye.. Wish you all the best guys! PiEcE..