Abstract: The karyotypes of four asparagus cultivars were studied using the tips of bud as material. The results showed that the morphological characteristics of the chromosomes in different cultivars were distinctive from each other. the karyotype of variety SEMILIA is 2n = 20= 10m+ 10sm; The varieties Uc72 and Uc157 are 2n = 20 = 8m + 12sm; and variety Mary Washington 500W, 2n = 20= 12m + 8sm. The results will offer a useful reference for the breeding of asparagus. The way to improve the zymolysis using buds as material was described, and the effect of the plant-culturing methods on cell-dividing period and the optimum sampling time were also discussed.