The Japanese pine bast scale, Matsucoccus matsumurae (Kuwana, 1905), is a destructive pest of pine trees in America, East Asia and Northern Europe. The spread of damage to black pine trees, Pinus thunbergii, of M. matsumurae was reported from all southern, and some eastern and west costal regions in Korea, under the name of M. thunbergianae which was newly described by Miller & Park (1987) as a new species. Historically, M. thunbergianae was synonymized with M. matsumurae by Booth & Gullan (2006), on the basis of molecular sequence data. However, the supporting data for the synonym is unavailable in any DNA database, such as GenBank and BOLD. Moreover, M. thunbergianae have been still used to the resent scientific studies in Korea. Here, we performed morphological and molecular comparison to review the result of Booth & Gullan (2006), using M. matsumurae from Fukuoka, Japan and topotype materials of M. thunbergianae from Goheung, Korea. Our data supported the opinion of Booth & Gullan (2006) following results: The morphological features of adult female and male of M. thunbergianae are identical to those of M. matsumurae. Also, DNA sequences (COI, 18S rDNA and 28S rDNA) of M. thunbergianae showed identical or very low genetic distances with those of M. matsumurae. From the regional sampling in Korea, M. matsumurae was newly found in Jeju and Seoul.