The somatic chromosome numbers among the various taxonomic characters about 17 taxa in Korean Aster and its allied taxa were investigated to review accurate scientific name and taxonomic rank. The somatic chromosome numbers of the treated taxa were invariable in same taxa, but variable among different taxa. The treated taxa were divided into two types by basic chromosome numbers, one type was x=9, the other x=8 and x=9 type was subdivided by polyploidy. The somatic chromosome numbers of Aster altaicus var. uchiymae, A. hyatae, Kalimeris chejuensis were reported firstly in this study, and based upon somatic chromosome numbers and leaf morphology, the plants, idenified as Aster pinnatifidus in Korea was considered variant of Kalimeris incisa.