The CW has renewed The Vampire Diaries, Arrow and Supernatural.“We said last year that one of our goals was to establish building blocks to grow on, and now with our new hit Arrow and fan favorite Supernatural on Wednesday night, and the continued success of The Vampire Diaries on Thursday, we’ve been able to do that,” said Mark Pedowitz, president of The CW. “Not only do Arrow, Supernatural and The Vampire Diaries perform well on-air, they’re also extremely successful for us both digitally and socially. I’m thrilled to have all three shows returning to our schedule next season.”
For The Vampire Diaries, this means the Kevin Williamson and Julie Plec-executive produced vampire drama will hit its fifth season (and pass the 100-episode threshold), while Arrow will return for its sophomore run and Supernatural will continue with a ninth season.
The Vampire Diaries has proven to be one of The CW’s most reliable and buzzed-about scripted efforts. Thus far in its fourth season, the drama  starring Nina Dobrev, Ian Somerhalder and Paul Wesley  has hovered around 2.85 million viewers. The Vampire Diaries‘ significance is not lost on the network, as it has become a launching-pad for new shows like The Secret Circle and Beauty and the Beast. The CW is also banking on a backdoor pilot that will air in late April to kick off a potential spinoff.
The second-season renewal for DC Comics adaptation Arrow comes as little surprise. The Stephen Amell starrer from showrunner Greg Berlanti launched big for the network in October  where it premiered away from the typical September clutter of premiere week  to a 1.3 rating in the advertiser-coveted adults 18-49 demographic and 4.14 million viewers. The opening marked the network’s best premiere since The Vampire Diaries and its most-watched telecast in three years.Arrow ranks as the network’s most-watched show this season, averaging 4.3 million viewers.
The CW’s longest-running show on the schedule, Supernatural, moved from its Friday time-slot this season as a lead-out for rookie breakout Arrow, and the move has proven beneficial, with an an uptick in viewership from when it followed Nikita.

Source : http://www.hollywoodreporter.com