The objective of this study was to evaluate potential of autochtonou yoghurt starter to produce exopolysaccharides to improve the texture of low fat yogurt as a popular and healthy food . This study was performed in two sections, microbiological and technological. In microbiological section, four indiginous locally isolated strains of Lactobacillus delbrueckii bulgaricus coded Is32, Is31, Is22 and IB 32 (Microbial collection, Food biotechnology Lab, Isfahan University of Technology) along with a pure commercial strain of Streptococcus thermophillus (Hansen Co., Denmark) were used as four starter culture samples. A commercial strain of L. bulgaricus coded 1.0 (Hansen Co., Denmark ), was also used as a positive control. Technological section of this study was carried out in three stages. In the first stage, yogurt prepared from local and industrial starter cultures, using restructured skimmed milk containing 0 and 3 percent fat and total solid of 12 and 15 percent. Physical properties of produced yogurts includin viscosity, syneresis, tensile and penetration were evaluated at first, seventh and fourteenth days of cold storage. Results of this stage showed that local starters IS31 and IB32 had better performance in terms of physical properties than other starters. Statistical Analysis of the results showed that fat, total solids and e starter had a significant effects (p 0.05) on physical properties of the yoghurt samples. In the second stage, Yoghurt was prepared from using IS31, IB32 and the commercial strain (1.0) (as the positive control). Results showed that fat and starters significantly (P 0.05) effected the physical properties of the products. Yogurts made by using IS31 ranked the best in terms of physical properties. In the third section of the research, one percent sucrose with 14 percent dried milk was used inorder to study the variation of nutrient media of starters. Results of this section showed that physical including sucrose, so that sucrose can be used as a good substiuent to increase the total solid of milk. In addition, studying the amount of polysaccaride splashed by local or industrial starters in second and third stages of the experiment showed that local starters specially IS31 produced more amounts of exopolysaccaride than industrial starters. as it can be recognized that ability of these local starters in production of exopolysaccarides could have been able to make good tissue properties in yoghurts. In final section, produced yoghurts in second and third sections of the search, were studied. The results of this section showed that yoghurts produced from local starters had more advantages than thosed produced from industrial starters, in terms of flavor, Smell, Tissue and appearale. Finally, results of this study showed that local starters can be good sulostituents for imported industrial starters. And can be a sufficient solution to remove the disadvantages in production of yoghurt with industrial starters by making desirable tissue properties in many case. Keywords : Yoghurt, Starter culture,Lactic acid bacteria,Physical property