Variations in levels of seed dormancy among conspecific populations are poorly understood. We aim to determine the variations in the level of dormancy in Rosa multibracteata along an elevational gradient, and to analyze the mechanisms underlying seed dormancy. The study was conducted in an arid valley in the eastern Tibetan Plateau at five elevations: 1700, 1900, 2100, 2300 and 2500 m. Achene traits were measured and physiological levels of dormancy were determined by measuring germination percentages of achenes treated with H 2 SO 4 scarification, warm stratification and cold stratification and combinations of those treatments. Achene size, mass and pericarp thickness increased with increasing elevation, but embryo width decreased with increasing in the arid valley. The level of dormancy generally increased with increasing elevation. The level of dormancy of the rose achenes is intermediate from sites at elevations of 1700, 1900 and 2100 m and deep at elevations of 2300 and 2500 m. Comprehensive analysis suggests that the elevational pattern of level of seed dormancy could be ascribed to intrinsically thicker pericarp and deeper physiological dormancy in the embryo, and extrinsically decreased temperature, increased precipitation and soil moisture at the higher elevations. The great variations of achene traits and levels of seed dormancy across elevations suggest a phenotypic differentiation exists within this rose species. Thus, habitat conditions and achene traits should be considered when selecting roses as materials used to propagate seedlings for ornamental purposes or plant restoration.