In order to get your dog to stop this behavior you have to stop rewarding it. What do pet owners usually do when the dog jumps up? Usually they look at the dog and say something like “OK, Rover, OK, down, down, OK, good dog, go away now, enough, OK…” and may even pet the dog during the episode. All this attention is PURE REWARD to the dog, and only encourages the jumping up behavior. What needs to be done is the withdrawal of all attention. When the dog jumps up, quickly turn away from the dog, fold your arms, make no eye contact and say nothing. Once the dog has settled down THEN give it loads of attention and serious petting. The dog will need to learn this with every family member and everyone should act the same way to be consistent.
Once the dog learns that jumping up gets it NOTHING, the behavior should lessen or stop. Often the combined use of the sit command to refocus the dog’s attention is a great way to speed the whole process. As the dog is calming down, give the sit command and reward the dog for the good sit. This is especially good when you are on walks and the dog encounters a human it wants to greet. Just before it gets excited, give the sit command, then reward the dog with food, petting, toys, etc. Get the human to come down to the dog’s level and greet the dog that way. A dog that is busy sitting can’t jump up if it’s on a leash.