Korean cultivated bramble, which is known as Bokbunja-ddal-gi is regarded to be originated from Korea native Rubus coreanus. However, little scientific evidence and significant morphological differences between Korean cultivated bramble(KCB) and R. coreanus throw doubt on the ancestry of KCB. This study was carried out to obtain phylogenetic information on KCB by comparing its nuclear genomic background with those of R. coreanus, black(R. occidentalis) and red(R. idaeus) raspberry, blackberry(R. lanciniatus) and R. crataegifolius. A total of 99 random amplified polymorphic DNA(RAPD) markers were generated and used for phylogenetic analysis of 76 Rubus accessions. Accessions of each species were grouped into each distinct subclade by the RAPD markers at a similarity coefficient of about 0.59. The KCB subclade formed a clade with R. occidentalis and R. crataegifolius subclades at a similarity coefficient of 0.47. The R. coreanus subclade formed a clade with R. idaeus, R. lanciniatus and R. crataegifolius subclades at a similar similarity coefficient. Only one KCB accession from Hoengsung was included in R. coreanus subclade. The accession shows leaf and flower characteristics different from the rest of the KCB accessions. The phylogenetic relationship inferred from the RAPD markers suggests that the nuclear genomic background of KCB accessions which show morphological similarity to black raspberry is more closely related to black raspberry than to R. coreanus. This brings about the need for close scientific evaluations on the ancestry of KCB at both morphological and molecular levels.