Evaluating the genetic relationship of sweetpotato varieties is an important prerequisite for understanding their genetic background and effectively utilizing germplasm resources. Using 23 pairs of InDel primers developed by our research group， genotype analysis was conducted on 305 registered sweetpotato varieties in China. A total of 56 bands were amplified， of which 53 bands were polymorphic， with a polymorphism rate of 94.6%. The average values of polymorphic information content （PIC）， Nei's genetic diversity index （H）， observed heterozygosity （Ho）， and expected heterozygosity （He） are 0.4098， 0.4451， 0.6003 and 0.4460， respectively. Group structure analysis indicates that ΔK reaches maximum at the number of groups K=2， with a small peak at K=4. The northern and Yangtze River sweetpotato zone are evenly distributed within the two groups， while the majority （72.97%） of the southern sweetpotato zone converge in group 2. The principal coordinate analysis （PCoA） shows that there is some convergence in the southern sweetpotato zone， but there is no clear cluster division overall. The clustering results divided the population into four main groups. The varieties in the northern sweetpotato zone and the Yangtze River sweetpotato zone were evenly distributed in groups I， II， III and IV， while the southern sweetpotato zone （77.03%） was mainly concentrated in group IV. This clustering result is basically consistent with population structure research and principal coordinate analysis. Genealogy analysis identified the main parental materials of 13 registered varieties， and there was a situation of repeated use of parents for forward and reverse breeding in each breeding unit. This article combines molecular marker results with pedigree information， preliminarily indicating that the registered varieties of sweetpotatoes in China have close genetic relationships and narrow genetic backgrounds， providing reference for germplasm innovation and new variety selection of sweetpotatoes.