Adam Rooney and David Goodwillie struck for the Dons in the first half with Peter Pawlett adding a third five minutes after the interval to secure an emphatic win.
In a one-sided affair, Niall McGinn thought he had put the Dons ahead early in the game but his effort was ruled out for offside.
Aberdeen did not have to wait long to seize the lead however as Rooney put the home side ahead with a powerful header from Niall McGinn’s corner on 20 minutes.
The home side doubled their advantage six minutes later when Goodwillie ghosted behind a sleepy County defence to nod McGinn’s lofted pass into the back of the net.
Dons pair Willo Flood and Ryan Jack were involved in a bizarre altercation minutes before half-time which earned both a yellow card.
The Staggies continued to offer minimal resistance after the break and went 3-0 down soon after the restart.
Flood broke clear down the right and his delivery was dummied by Rooney, allowing Pawlett to score with the help of a deflection.
The only worry for Dons boss Derek McInnes was when McGinn limped off holding his hamstring as he was replaced by Jeffrey Monakana.
The result moves Aberdeen up to seventh in the table while pointless County remain firmly rooted to the bottom.