In order to understand the chromosome structure of sweet potato (Ipomoea batatas cv. Xushu 18), molecular cytogenetic analyses were carried out on I. batatas. by using 45S rDNA fluorescence in situ hybridization (45S rDNA-FISH), self genomic in situ hybridization (self-GISH), and silver staining techniques. Twelve, sixteen, and eighteen regions were silver stained in the interphase nucleus of I. batatas. The results of FISH analysis demonstrated 16 or 18 signals with different intensity on chromosomes of I. batatas. Self-GISH analysis showed that the intensive signals on I. batatas mitotic chromosomes were distributed along the chromosomes. However, the signals located in centromeric, subcentromeric, and telomeric regions were stronger and denser than those in other regions.