Given the health concerns associated with excessive fat intake, reducing the fat content in lipid-based products such as mayonnaise has become a critical priority. This study aimed to achieve dual objectives: firstly, to prepare RS4-type resistant starch by the modification of starch with acyl groups of varying chain lengths. Secondly, to investigate how different types of acylated starch and varying fat substitution levels (40 % and 80 %) affect the viscoelastic and textural properties of low-fat mayonnaise prepared with these acylated starches. The study results demonstrate that succinate modification significantly enhances the rheological properties of starch, with a peak viscosity increased by over 3 times. Furthermore, compared to acetylated starch (ACS) and octenyl succinylated starch (OSAS), succinylated starch (SCS) exhibits the highest resistant starch content, reaching 48.08 ± 0.54 %. As a partial fat substitute, low-fat mayonnaise prepared using SCS exhibits higher storage modulus (G'), hardness (10.33 ± 0.23 g), and adhesiveness (0.77 ± 0.05 mJ) than samples prepared with OSAS and ACS. However, these values remain below those of full-fat mayonnaise. Additionally, the particle size distribution of the low-fat mayonnaise ranges from 3.13 to 4.89 μm. Principal component analysis reveals that low-fat mayonnaise prepared with SCS and OSAS exhibits similar properties. While starch properties impact the rheological characteristics of low-fat mayonnaise, the specific effects vary depending on the modification method of the starch. In summary, SCS is identified as an ideal fat substitute for mayonnaise, offering a promising strategy for the development of low-fat food products.