Jumping Up On People
This is a very common complaint that people have about their dogs. First, if you have a puppy, the prevention of this problem is much easier than its cure. Most people allow their puppies to run up and jump on them. The owner thinks it is cute. When the puppy does this, the owner will usually pick the puppy up and fuss over the puppy. This behavior on the part of the owner shows the puppy that jumping is appropriate behavior which is rewarded.
Instead of allowing the puppy to jump in the first place, teach the puppy to sit when he comes to you.
If your puppy jumps, do not pick him up, instead gently coax the puppy into a sitting position (or whatever position you want) and reward the pup for doing it.
If your dog is older, reject the jump with your body by holding your hands high above your head as you turn your back to the dog while giving the command "OFF." As soon as your dog has all four feet on the ground turn around and praise your dog.
For more difficult cases see your dog trainer or behaviorist.