Allozyme variations of Tristram's jird Meriones tristrami, which is distributed in the steppe and semiarid areas of Turkey, were studied using 24 loci of 83 specimens from ten locations in Turkey. Seven loci were found to be polymorphic. According to the patterns of allozyme variation, the percentage of polymorphic loci was 12.5. FST was found to be 0.44, indicating high genetic variations among M. tristrami; accordingly the Nm value (0.3157) appeared quite low. The UPGMA dendrogram, based on genetic distance, showed that the populations established two very close subclusters, and supported the idea that the westernmost population connected to the northern part of the central Anatolian population. As expected, the eastern population appeared to be more divergent due to geographic distance. Our findings supported that genetic isolation among these subpopulations might be caused by geographic isolation.