Aegilops tauschii Coss., the D genome progenitor of hexaploid bread wheat (Triticum aestivum, AABBDD), is considered the most promising genetic resource for wheat breeding. It has a wide natural habitat in Central Eurasia, spreading from northern Syria and Turkey to Western China. The morphological and physiological variations of Ae. tauschii were analyzed using a diverse collection of 343 accessions that represent the entire habitat. These 343 accessions were evaluated for two seasons under field condition at the Arid Land Research Center, Tottori University, Japan to clarify the genetic variation of this species. We investigated eighteen morphological and physiological traits and found a wide variation among all accessions. Based on the correlation between the phenotypic traits and the geographical origin we could create a geographical map illustrating the hot spots of the variation of the trait to facilitate utilization of the accessions preserved in the gene banks by suggesting the germplasms that might harbour the desirable traits based on the geographical origin. For genetic characterization, these accessions were genotyped using the DArTseq platform. Using the genotypic data, the accessions could be divided into two main lineages and other sub-lineages. Although, the genetic diversity and the morphological variation of Ae. tauschii has been intensively studied, this study in addition to the morphological traits, evaluated the variation of some physiological traits such as chlorophyll content, canopy temperature and normalized difference vegetative index, that known to be associated with plant stresses tolerance, using a greater number of accessions (343 accessions) than that used in the previous studies (100-210 accessions). We were able to predict the probable geographical origin for more than 200 accessions based on their genetic and phenotypic similarities with accessions with known geographical origin. Moreover, based on the spike morphology and genetic similarity we could provide the subspecies structure for many accessions. The information in this study may improve our understanding of the evolution and dispersion of Ae. tauschii and may facilitate breeding of wheat with greater genetic diversity.