Biodiversity of wild relatives of Cataegus were studied in North-West region of Damascus countryside located between latitudes 33.36 -33.58 N and longitudes 35.58-36.39 E including 7 sites and 21 subsites ranging from Zabadane to Alnabk. Results showed that the most of the individuals in the search area belonging to C. azarolus and var. aronia and rare individuals ere found to belong to C. monogyna. The study on the level of intraspecific variability showed the presence of of three taxanomic groups, each had been characterized with morphological and environmental qualities.The study also pointed to the where of these species and their different types are located and to the exist of corrlation between environmental factors and morphological variables.