The chemical affinities among 12 species of Viola from Jeju Island are investigated by thin-layer chromatography for their MeOH soluble and aglycon parts. They are classified into three groups which are closely related to those of morphological classification: the first allience-Viola hirtipes, V. chaerophylloides, V. meta-japonica, V. keiskei var. okuboi and V. violacea; the second allience-V. xanthopetala, V. ovata-oblonga, V. acuminata var. acuminata and V. grypoceras; and the third allience-V. pachyrhiza, V. phalacrocarpa and V. mandshurica var. ciliata. The first allience consists of the species without stem which have PA value greater than 50% with one another. V. hirtipes and V. chaerophylloides show closer affinity among the taxa of this allience. The second allience consists of the species with stem, of which PA value are about 50%. The third allience consists of the species without stem which have PA values lower than 50% when compared with any other taxa.