Abstract: In order to explore the the genome size and characteristics of the Nuphar pumila (Timm) DC, this study selected three N. pumila. samples numbered: KMPPC01, KMPPC02, and KMPPC03 for flow cytometry detection. The KMPPC01 was selected for high-throughput sequencing. Combined with bioinformatics methods such as K-mer analysis, conducted preliminary research on the genome of N. pumila. The results are as follows: (1) The genome size of N. pumila was determined to be approximately 2187.12 Mb by flow cytometry and the converted C value was approximately 1.12 pg; (2) The raw data obtained by high-throughput sequencing was 111.76 Gb, and the clean data obtained after filtering was 108.39 Gb; (3) K-mer analysis showed that the genome size of N. pumila was 2094.71 Mb, the GC content was 38.20%, the heterozygosity was 1.89%, the proportion of repeated sequences was 62.63%. In summary, the genome of N. pumila. is a highly heterozygous and highly repetitive complex genome with a size of approximately 2094.71 Mb～2187.12 Mb.