Abstract: The study objectives were to investigate the structural characterization and rheological properties of acetylated cassava starch to provide a comprehensive theoretical basis for its development and utilization in food processing. Structural characterization of both acetylated and non-acetylated cassava starch was performed by infrared spectroscopy, X-ray diffraction, and thermogravimetry, and the fluidity, thixotropy, and dynamic viscoelasticity of acetylated cassava starch were also determined. It was found that the acetylated starch showed a characteristic acetyl-group absorption peak at 1730 cm⁻¹ and that while acetylation did not alter the crystalline shape of the starch, it reduced its thermal stability. The rheological results showed that the acetylated starch was a pseudoplastic fluid with shear-thinning behavior, and its flow curve conformed with the Cross model. The thixotropic ring area increased sharply as the solution concentration increased and showed good elastic-solid properties, and the modulus and complex viscosity results verified this conclusion. This study showed that acetylated cassava starch has good rheological properties which effectively enhance its thickening properties, suggesting its potential for wide use in the food processing industries.