Morphological features and composition of ISSR DNA fragments were studied in species of the genus Tulipa L. A comparative analysis of the data obtained was carried out and an attempt was made to clarify the species belonging of plants. Plants obtained from various sources were studied. It was found that representatives of the genus Tulipa L. from the two subgenera Tulipa and Eriostemones are well separated not only morphologically, but also by the composition of ISSR fragments. At the intra- and interspecific level, the results for morphological traits and molecular data differed. Interspecific and intraspecific differences were more clearly traced in the complex analysis of morphological features and ISSR PCR data. All samples obtained in the form of bulbs and renewed vegetatively had an identical set of ISSR fragments. Plants grown from seeds were characterized by a significant variety of molecular markers and had both species-specific and in-dividual genetic variability. It was found that the samples obtained and registered as the Tulipa urumiensis Stapf are the yellow-flowered form of the Tulipa tarda Stapf, and a sample received as the Tulipa turkestanika Regel is the Tulipa bifloriformis Vved. Thus, a comprehensive study of both the data of fragmentary DNA analysis and morphological features, provided a sufficient number of DNA samples, makes it possible to clarify the species of tulip plants, and also allows us to assess the genetic diversity of the genus Tulipa.