The objective of this work was to study the effect of different dietary fibers on the rheologyical , physicochemical and sensory properties of yoghurts fortified with these fibers . Ground wheat germs , flour oat's ,fibers of top of sugar can and ground barely addition were used and added at 0.5, 1.0,1.5 and 2.0% (w/w) to yoghurt milk. Yoghurt samples prepared with nutritional additives or traditional were compared. Results show the changes in the chemical and  sensory properties of Yoghurt from different treatments were followed during storage at refrigerator (4-5°C) for 15 days. As the percentage of food additives increased the coagulation time decrease. Total solid ,ash on dry matter, soluble nitrogen ,non protein nitrogen on total nitrogen and total volatile fatty acid increased in all treatments but fat on dry matter values decrease compare with control cow's yoghurt. Titratable acidity values of various yoghurt treatments gradually increased during storage period 15 days. pH value was of opposite behavior of titratable acidity for all treatments of yoghurt made from buffaloe's and cow's milk .It could be observed from the organoleptic scoring that both oat and barley treatments were the best additives for improving the body characteristics of cow's yoghurt to be compare with that made from buffalo's milk one.