,  , The black pine bast scale, Masucoccus thunbergianae (Hemiptera: Margarodidae), is a serious pest of the Japanese black pine, Pinus thunbergii, in Korea. The distribution of the black pine bast scale was examined, looking overall at 686 towns (eup), townships (myeon) or neighborhoods (dong). There were Japanese black pine (Pinus thunbergii) forests in 91 cities, counties (gun) and borough (gu), in seven provinces and three metropolitan cities during 2010. Black pine bast scale were found in 64.8% of cities or counties or borough (59) in 7 provinces and 3 metropolitan cities, and were distributed in all South Costal regions, Pohang in East Costal region and Boryeong in West Costal region. Chungcheongbukdo, Daejeon and Jeju did not have black pine bast scale. All the gu regions in Busan had black pine bast scale, of which the area with the highest prevalence was Haenam in Jeollanamdo (1.713 crawlers/0.785 cm 2 ). Songji-myeon had the highest occurrence rate (6.36 crawlers/0.785 cm 2 ) from the towns, township and dong. The density of black pine bast scale in twigs was highly correlated with percentage of the sample with scale (Correlation coefficacy=0.89).