Mg　delta-doped　GaN　epilayers　have　been　grown　by　metalorganic　chemical　vapor　deposition,　and　their　characteristics　have　been　investigated.　It　is　shown　that　not　only　the　p-type　conduction,　but　also　the　overall　quality　of　p-GaN　is　improved　by　delta-doping.　It　is　observed　that　the　dislocation　density　is　reduced　due　to　the　growth　interruption.　A　pre-purge　step　has　been　employed　during　delta-doping　process,　but　the　carrier　concentration　was　decreased　by　the　pre-purge.