The effect of apple and wheat fibers was studied on viability of Lactobacillus acidophilus in symbiotic yogurt and its physicochemical, sensory and rheological properties during 29 days storage at 5±1 ^ºC. The results of analysis showed that the number of Lactobacillus acidophilus in control and sample containing 0.5% fiber were reduced by 1 and 0.5 log cycle respectively and reached to 6 and 6.85 log cycle respectively at the end of storage period. But the sample containing 1% of fiber showed 0.25 log cycle increase in the number of Lactobacillus acidophilus at the same time and reached to 7.6 log cycle. This increase was higher in samples containing wheat fiber in comparison with those containing apple fiber (p<0.05). The samples containing fiber showed higher viscosity and lower syneresis in comparison with those not containing any fiber. The effect of wheat fiber on viscosity was higher than the effect of apple fiber (p<0.05). Increasing the amount of both fibers also caused samples to gain lower score for their color and taste. This decrease was obvious in samples containing apple fiber. Totally the samples containing 0.5% wheat fiber where known as best color and taste point of view between samples containing fiber. So it was concluded that using wheat fiber at the rate of 0.5% not only improved texture and chemical properties of yogurt but it could also provide the consumer satisfaction.