Purpose. To analyse the qualitative and quantitative composition of volatile organic substances (VOS) in the petals of six species of dog-rose in the collection of M. M. Gryshko National Botanic Garden of the NAS of Ukraine for further bree­ding. Methods. Volatile organic substances were obtained by steam distillation. VOS was determined using gas chromato­graphy (Chromatograph Agilent Technologies 6890). Results. The qualitative and quantitative composition of volatile organic substances in the petals in such species as Rosa L. (R. roullettii HCh (Correvon), R. multiflora Thunb., R. pimpinellifolia L., R. canina L., R. centifolia L., R. rugosa Thunb.) was investigated. According to the results of the research, 105 VOS were discovered in the dog-rose petals, among which 11 were not identified. The dog-rose petals of identified VOC contained 16 components which share exceeds 5%, 31 – was ranging from 1% to 5%, 47 – was less than 1%. They belonged to different groups including monoterpenoids, sesquiterpenoids, sesquiterpene alcohols, saturated unbranched hydrocarbons etc. The largest number of components were identified in the petals of R. roulettii (49) and R. centifolia (45), while the number of identified components in species R. multiflora (33), R. rugosa (31) and R. canina (30) was relatively smaller. All studied dog-rose species were characterized by the presence of such saturated unbranched hydrocarbons as decan, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nanodecane, heneicosane, tricosane, tetracosane, pentacosane, heptocosane, hentriacontane. Triterpene hydrocarbon squalene is the important component of the VOS complex in dog-rose pen tals. b-phenylethyl alcohol to be one of the main components of the rose essential oils was found during investigation in the following four dog-rose species as R. centifolia (0.61%), R. pimpinellifolia (3.56%), R. rugosa (4.24%), and R. multiflora (5.43%). Significant content of dihydro-b-ionol (18.46%), dihydro-b-ionone (0.69%), thias­piran A (1.35%), and thiaspiran B (2.17%) were revealed in the petals of R. roulettii, which also have an influence on the aromatic bouquet of the rose oil. Conclusions. For the first time, 105 volatile organic substances were found in the petals of six species of dog-rose, 11 of which were not identified. It was found out that the largest number of components were identified in the petals of R. roulettii (49) and R. centifolia (45). The number of VOS identified in species R. multiflora (33), R. rugosa (31), and R. canina (30) was relatively smaller. Component composition of VOS in the petals of studied dog-rose species is an important constituent in breeding investigations of prospective producers for the various purposes of use.