If your talking about a grizzly around your property, fireworks like m80's, peppersprays and finally a shotgun blast with bird shot usually runs them off. Repeat offenders need to be trapped and relocated by professionals.
If your talking about being attacked the old play dead still holds for grizzlies as they don't like to eat their meat fresh and rather let you rot a bit. If you fight they will continue to attack, and if you run they will chase you and they can run about 10 miles faster than the fastest human. They swim and climb trees as well. If camping or hiking in grizzly areas carry a side arm, something powerful like the 38 or 45, and pref magnum.