1. The karyotypes of 15 collections belonging to 9 races of European species of Aster are reported.
2. The basic chromosome number for the European species of Aster is 9.
3. Two polyploid levels, namely, triploidy and hexaploidy have been found in the European species of Aster for the first time.
4. The karyotypes of the European species of Aster are similar to those of the Asiatic species. This is an indication that the European and Asiatic species of Aster have their ancestral forms in common.