Geographical variation in soluble sugar concentrations in seeds from oriental beech (Fagus orientalis Lipsky) trees of different origins in Turkey was determined using high performance liquid chromatography. The results demonstrated that the most significant soluble sugars, in order of importance, were sucrose, glucose, and fructose. All free sugars varied significantly (P < 0.05) within and among populations. In general, both total and soluble sugar levels tended to be higher in northern populations compared to southern ones. Cluster and discriminant analyses divided seed sources into 3 distinct groups corresponding to a north, south, and west division of oriental beech populations.