The morphological analysis and cytological study of Indigofera kirilowii Maxim. and Indigofera korean Ohwi were undertaken to assess the numbers and ranks of taxa that usefully could be recognized. I, koreana, previously recognized as I. kirilowiii, was separated from I. kirilowii in hairiness on leaflets, flower size, pollen exine sculptures, geographical distribution and chromasome number. Chromosome count of 2n=32 (tetraploidy) from I. koreana was obtained for the first time. The results of principal components analysis (PCA) on a matrix of 11 populations of Korea by 19 morphological characters indicated that two species could be recognized by the first principal component, contribution of which for the total variance is 63.2%. Our results supported that I. koreana could be clearly distinguished from I. kirilowii. Since the quantitative differences between the two varieties, I. kirilowii var. coreana and var. Kirilowii, were smaller, a nomenclatural synonymy was developed for them, ie, var. kirilowii.