Chemical composition and neutral DNA sequences of three pairs of morphologically close Ligularia species, L. subspicata/L. lamarum, L. anoleuca/L. veitchiana, and L. franchetiana/L. oligonema, were studied. Samples L. subspicata and L. lamarum were collected at 21 locations (Table 1 and Fig. 1). Both L. subspicata and L. lamarum samples could be grouped into two based on the presence or absence of furanoeremophilanes, but the two species were not distinguished in their chemical components. The major components of the Ehrlich-negative type were eremophilane-8-one derivative(s), while ligularol, subspicatins, and their derivatives were isolated from Ehrlich-positive type. The two species were not separate in the base sequences of ITS region as well. Subspicatins(5-7) were isolated as the characteristic new compounds of the species, and their structure was determined by spectroscopic methods. Chemical and genetic study of L. anoleuca and L. veitchiana revealed that the two species are not close to each other despite morphological similarities. From L. veitchiana, euparin and its derivatives were isolated, while furanoeremophilanes were isolated from L. anoleua. Furanoeremophilanes were isolated from both L. franchetiana and L. oligonema, belonging to the section Corymbosae series Retusae. Howeverk alignment of the ITS sequences of the sepcies showed that L. oligonema was separated from the other species belonging to the same section/series. These results suggest that chemical evolution in this series is complex.