The stone sculptures in Gyeongbokgung Royal Palace are mainly composed of granite (884 sculptures, 96.7%) and marble (25 sculptures, 2.7%) that originated in several different quarries. Main deterioration forms are crack (24%), break-out (21%), exfoliation (36%), granular disintegration (9%) and blackening (20%). Crack and break-out are dominant contributors to high physical deterioration degree, and blackening is major weathering form of intensive discoloration. The Geunjeongjeon and Pumgyeseok areas require urgent and high conservation maintenance with short-term periodic monitoring since proportions of 3-grade deterioration were calculated higher than others as 55% for Gyeonghoeru, 29% for Geunjeongjeon, 11% for Pumgyeseok area. The Pumgyeseok (officials' rank stone), especially, needs intervention for protective facility due to its material vulnerability to weathering in outdoor environment.