The main goal of this research was to produce hydrogel and bigel based on soy protein isolate (SPI) containing carboxymethyl cellulose/tragacanth (CMC/TG) and corn oil (CO) and its use as an oil substitute in the formulation of low-fat mayonnaise. Based on this, hydrogel and bigel produced at the level of 30, 60 and 90% replaced fat and 7 types of mayonnaise were prepared and their physicochemical properties were investigated. SEM images showed that the gel structure was uniform in the produced bigel, but the presence of corn oil emulsion inside the hydrogel composition was visible. Replacing fat with hydrogel and b-gel did not have a significant effect on acidity and pH. The increase of fat replacement with hydrogel and bigel increased 4 factors of viscosity, elastic modulus (G’), viscous modulus (G”) and hardness, and the increase of these 4 factors increased the strength of the product texture. The increase of hydrogel and bigel increased the stability and reduced the adhesiveness of the product. By increasing the replacement percentage of hydrogel and bigel in the mayonnaise sample, the amount of fat decreased, and the main goal of the research in the production of low-fat mayonnaise was achieved. The highest amount of peroxide was in the control sample without hydrogel and bigel. Bigel had a great effect on the reduction of water activity, so that the lowest water activity was related to the sample with 90% replacement of Bigel. Both hydrogel and bigel increased lightness. Considering the inherent color of mayonnaise, which is white, increasing its lightness is a desirable phenomenon. The general result is that the use of hydrogel and bigel in the preparation of low-fat mayonnaise can improve the chemical and physical stability of this product. In addition, this study showed that the use of hydrogel and bigel can be used as a stable oil substitute in the preparation of mayonnaise.