Abstract:Chromosome number and karyotype of Cycas debaoensis Y. C. Zhong et C. J. Chen from China isreported for the first time, which has karyotype formula of K(2n)=2x=22=6m+4sm+12T, belonging to Stebbins'3B type. Total length of chromosomes is 93.49μm, and ratio of asymmetric karyotype (As.K%) being 85.53%. The result reveals that the karyotype of this species is basically similar to that of C. micholitzii Dyer and C.multipinnata C. J. Chen et S. Y. Yang.