Who play the characters of ben ten?

You're asking about the voice actors for Ben 10, right? Here are some of the main voice actors for the various Ben 10 series:

Ben Tennyson:

* Original Series (2005-2008): Tara Strong

* Ultimate Alien (2009-2010), Alien Force (2008-2010), Omniverse (2012-2016): Yuri Lowenthal

* Ben 10: Omniverse (Rebooted Series, 2016-2018): Ryan Kelley

* Ben 10 (2016 Reboot): Rex Lee

Gwen Tennyson:

* Original Series (2005-2008): Dee Bradley Baker

* Ultimate Alien (2009-2010), Alien Force (2008-2010), Omniverse (2012-2016): Meagan Smith

* Ben 10: Omniverse (Rebooted Series, 2016-2018): Judith Barsi

* Ben 10 (2016 Reboot): Courtney Taylor

Kevin Levin:

* Original Series (2005-2008): Michael Reisz

* Ultimate Alien (2009-2010), Alien Force (2008-2010), Omniverse (2012-2016): Greg Cipes

* Ben 10: Omniverse (Rebooted Series, 2016-2018): David Hornsby

* Ben 10 (2016 Reboot): Roger Craig Smith

Other Major Characters:

* Max Tennyson: Richard Steven Horvitz (Original Series), Jeff Bennett (Alien Force, Ultimate Alien, Omniverse), John DiMaggio (Rebooted series)

* Vilgax: Dee Bradley Baker (Original Series), David Boat (Alien Force, Ultimate Alien, Omniverse), Fred Tatasciore (Rebooted Series)

This is just a sampling of the voice actors involved in the various Ben 10 series. You can find a more complete list on the Ben 10 wikia or on websites like IMDb.