What kind of dog is this?

to me it looks like a german shepherd puppy

It's a Rottweiler puppy.

if you had showed e the tail i would have more information but to my guess its a Tibetan mastiff or another Tibetan dog mixed dog look it up for the puppy looks. This pup looks very similar, ask for more info

Well, it looks like it will grow up to be quite a big dog...