In order to understand the genetic background and genetic relationship of 148 S. tuberosum of tetraploid potato at home and abroad, the whole genome was resequenced through the thirdgeneration highthroughput sequencing method. Using SNP as molecular markers, genetic similarity coefficient as indicator and pedigree information, we analyzed the genetic diversity of the population by using a combination of population structure and cluster analysis. The results showed that: (1) 1 209 969 highquality SNP loci were obtained after effective filtering and screening. The number of SNP loci clearly located at the chromosome level was 1 192 472, accounting for 98.55%. Except for chromosome 11, which has no loci distribution, chromosome 5 has the most, Chromosome 7 is the least. (2) The genetic similarity coefficients among various breeds ranged from 0.784 to 0.958, with an average of 0.842, mainly concentrated in the range of 0.800 to 0.880, with 10 604, accounting for 97.5%. (3) The structure analysis showed that 148 materials were divided into 6 groups, 36 varieties with Q value> 0.6, accounting for 24.3%. Among varieties with a relatively single genetic background, 16 varieties bred in North China accounted for 44.4%. 13 foreign varieties accounted for 36.1%, and the two together accounted for 80.5%, indicating that the genetic components of bred varieties in North China and foreign varieties have a higher percentage of genetic components than other regional varieties. (4) The results of cluster analysis showed that 148 potato varieties were divided into 3 groups. The varieties of ‘Zhongshu Series’, ‘Longshu Series’ and ‘Jizhangshu Series’ clustered together have a certain geographic region, and other varieties of different geographic origin. The interlaced distribution of potato varieties shows that the differences in breeding areas are not necessarily related to genetic relationships. Breeding units frequently introduce each other, and there are gene exchanges between different areas during the selection and breeding of new varieties. The results of structure analysis and cluster analysis are basically consistent and mutually verify. Studies have shown that most S. tuberosum have a high genetic similarity, and the genetic background is not rich enough. It is urgent to introduce new germplasm in breeding to broaden the genetic basis.