Fat plays a key role in maintaining the good quality of salad sauces， and its variation affects the texture properties of salad sauces. Rubbing test is a common method used to evaluate some of the texture properties of food products. In order to investigate the effect of fat content on the smoothness of salad sauces， particle size measurements and texture profile analysis (TPA) was performed for commercial salad sauces with different fat contents， and then the friction properties were investigated using the rubbing substrates constructed by polydimethylsiloxane (PDMS) and simulated saliva. The results showed that the particle size of salad sauces increased with the decrease of fat content， which was significantly correlated with their coefficients of friction (P < 0.05). But there was no significant correlation between their TPA parameters and coefficients of friction. Under the effect of saliva， the average coefficient of friction of high-fat salad sauces was significantly lower than that of low-fat salad sauces， and coefficients of friction functioned as a linearly decreasing relation with the increasing fat content. Reasonably setting parameters was more favorable to characterize the difference in the smooth levels of salad sauces. This study can provide a better insight into the development of low-fat salad sauces and other similar health foods.