Based on the morphological characteristics of the ustilospores, the geographical distribution and host preference of common bunt Tilletia foetidae and T. caries on bread wheat and durum wheat in Syria has been studied. The spore wall structure forms the most feasible and convenient method for differentiation between the two pathogens. Accordingly, T. foetidae is the most prevalent pathogen in North Syria and the predominant pathogen in the bread wheat. T. caries was widespread in durum wheat in South Syria. This phenomenon has been confirmed in artificial inoculation tests and discussed as host-preference in T. foetidae and T. caries irrespective of the geographical area in which the disease is observed and irrespective of the environmental conditions. T. foetida, however was the predominant pathogen on bread wheat, while T. caries preferentially attacks durum wheat.