###### Abstract  
As the distribution center of _Rosa_ in the world, China has abundant wild germplasm resources, which can contribute to the breeding of modern roses. To explore the potential value of wild roses distributed in the Sichuan-Tibet region, solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) were used to determine the volatile organic compounds (VOCs) in _Rosa willmottiae_ flowers at three flowering stages (bud stage, initial flowering stage, full flowering stage, Meanwhile, we compared the VOCs of _R. willmottiae_ with different phenotypes (double flowers and single flowers). A total of 74 volatile compounds were identified. The results show that the essential substances belong to alcohols and terpenids. The main volatile organic compounds are 2-phenyl ethanol (20.49%), benzyl alcohol (10.69%), 6-m-maliene (8.66%), geranyl acetate (8.47%), and (+)-\(\alpha\)-long pineine (6.127%). Different flowering stages had great influence on the volatile profile, from the bud stage to full flowering stage; the content of terpenids released decreased by 6.17%, whereas alcohols and esters increased by 8.58% and 11.56%, respectively. The chemical diversity and the content of the main components with a different phenotype were not significantly different. Our result will provide a theoretical basis for the development and utilization of _Rosa willmottiae_ in Sichuan and Tibet.  
Rosa willmottiae; volatile profile; flower development; SPME-GCMS 202227124  
altitude of 1300-3800 m. The type specimens of _R. willmottiae_ were collected from Songpan County, Sichuan Province. According to records, _R. willmottiae_ is a medicinal plant which can be used to treat feverish vomiting blood, hot polydipsia, epigastric distension, thirst, diarrhea, malaria, bleeding from knife wounds, and irregular menstruation [13]. Similar to other scented roses, _R. willmottiae_ has a pleasant scent. However, its floral composition is rarely reported, only its petal aroma volatile organic compounds (VOCs) is [14], but how the volatile profile of the whole flower changes with the flowering stage is unknown. In addition, double flower mutants of _R. willmottiae_ occur in the wild, but how the floral phenotype under natural mutation affects floral aroma components is also unknown.  
Aroma volatile organic compounds are often difficult to measure, collect, and analyze, so they must rely on relevant technologies [7; 15]. There are three methods for extracting floral components from plants: traditional water distillation, solvent extraction, and solid-phase microextraction (SPME) [16; 17]. High temperature in traditional water distillation methods may result in the loss of some components, while solvent extraction methods often affect the determination of the plant VOCs due to residual organic solvents [18; 19]. However, SPME can maximally maintain the integrity and authenticity of the flora VOCs [20]. This method is simple, rapid, and effective, with a low detection threshold [21].Therefore, SPME is the best method to extract volatile organic compounds and has been widely used [9; 22]. Gas chromatography-mass spectrometry (GC-MS) is currently the most commonly used method for the determination of volatile substances [23].  
In order to understand the flora volatile profile of _Rosa willmottiae_, this study used SPME + GC-MS to determine the main components: (1) to explore the changes of volatile organic compounds at different flowering stages [24]; (2) to analyze the effect of petal number variation on the fragrance composition of _R. willmottiae_; and (3) to excavate the floral components with economic value, to provide a scientific basis for developing new raw materials of plant essential oil, to cultivate new varieties, and to lay a theoretical foundation for the development and utilization of _R. willmottiae_ in the Sichuan-Tibet region.