Last years league champions Prachinburi United and runners up Maptaphut Rayong failed to qualify from the 2014 Regional League Division 2 championsleague round.
Sriracha Ban Bueng were relegated from the 2014 Thai Division 1 League.
Pakchong United and TG Rayong have withdrawn from the 2015 campaign.
Kaeng Khoi TRU joined the newly expanded league setup.
Thawi Watthana, Bangkok Bangkok-Thonburi University Stadium ?