<jats:title>Abstract</jats:title><jats:p><jats:italic>Rosa rugosa</jats:italic>, commonly known as rugged rose, is a perennial ornamental shrub. It produces beautiful flowers with a mild fragrance and colorful seed pods. Unlike many other cultivated roses, <jats:italic>R. rugosa</jats:italic> adapts to a wide range of habitat types and harsh environmental conditions such as salinity, alkaline, shade, drought, high humidity, and frigid temperatures. Here, we produced and analyzed a high-quality genome sequence for <jats:italic>R. rugosa</jats:italic> to understand its ecology, floral characteristics and evolution. PacBio HiFi reads were initially used to construct the draft genome of <jats:italic>R. rugosa</jats:italic>, and then Hi-C sequencing was applied to assemble the contigs into 7 chromosomes. We obtained a 382.6 Mb genome encoding 39,704 protein-coding genes. The genome of <jats:italic>R. rugosa</jats:italic> appears to be conserved with no additional whole-genome duplication after the gamma whole-genome triplication (WGT), which occurred ~100 million years ago in the ancestor of core eudicots. Based on a comparative analysis of the high-quality genome assembly of <jats:italic>R. rugosa</jats:italic> and other high-quality Rosaceae genomes, we found a unique large inverted segment in the Chinese rose <jats:italic>R. chinensis</jats:italic> and a retroposition in strawberry caused by post-WGT events. We also found that floral development- and stress response signaling-related gene modules were retained after the WGT. Two <jats:italic>MADS-box</jats:italic> genes involved in floral development and the stress-related transcription factors <jats:italic>DREB2A-INTERACTING PROTEIN 2</jats:italic> (<jats:italic>DRIP2</jats:italic>) and <jats:italic>PEPTIDE TRANSPORTER 3</jats:italic> (<jats:italic>PTR3</jats:italic>) were found to be positively selected in evolution, which may have contributed to the unique ability of this plant to adapt to harsh environments. In summary, the high-quality genome sequence of <jats:italic>R. rugosa</jats:italic> provides a map for genetic studies and molecular breeding of this plant and enables comparative genomic studies of <jats:italic>Rosa</jats:italic> in the near future.</jats:p>