[Objective]The study was to analyze the karyotype of Allium macrostemon Bunge in Laizhou City of Shandong Province.[ Method] The root tip of A. macrostemon was pretreated with 8-hydroxyquinoline solution, fixed, dissociated and stained for preparing the glass slide to reveal the chromosome number via the microscopic examination; the sparse cells with good chromosome morphology were photographed under microscope. [ Result ]Allium macrostemon Bunge in Laizhou City introduced in this study was tdploid; its somatic chromosome number was 24 and karyotype formula was K（2n） =3x=24m（2SAT） ＋ 1Bs, thus the karyotype belongs to 1A type. One of the chromosome No. 3 contained satellite, and chromosome deletion may be existed in one of the chromosome No. 5. In addition, B chromosome was observed in some cells.[ Conclusion] This introduction of triploid A. macrostemon found in China was the first time.
