I want to make a barbarian whit only fur armor and a two handed sword.
But can someone tell me if there is a perk like ''natural armor'' or ''hard skin'' to make im last longer in battle.

Thanks,

Just get the standard armor improvement perk levels. Don't expect miracles with fur though.

There are perks under the light armor skill tree that increase a light armor users resistance to attacks.

Raise Smithing up to 100, but don't put any perk on it (maybe except the two required to upgrade magical armor/weapons, if applicable), and concentrate on your Light Armor skill & perk tree and your weapon of choice' ones. With Smithing plus using all the Fortify Smithing stuff you can get (including Blacksmith' elixirs), you can easily upgrade your Fur armor to Legendary and beyond. I bet you can easily reach more than 400 AR, only with that and Light Armor maximized. And if you want an extra boost, pick the Lord stone birthsign (+ 50 AR and +25% Magic Resistance).

As for weapons, you can get your hands into Ebony stuff without having to put perks on Smithing, but if you want to do extra damage with them you'll eventually have to put the required ones to fully upgrade your weapons, or to create Daedric ones.

Barbarians are fun.
My Nord Barb wears only hide bracers and imperial leather boots with ragged trousers and no top, oh and a circlet on his head. He uses 2handed greatswords with major block skills and the occasional sneak.
It`s hard but a helluva lot of fun

Patch 1.2 hasn`t helped much either since he has no resists now.