The properties and structure of native taro starch and three modified starches (ultrasonically modified starch, malic acid modified starch, and ultrasound-malic acid modified starch) are compared and analyzed in this work. Experimental results demonstrate that ultrasound and malic acid change the properties and structure of taro starch. Compared with the native starch, the combination of ultrasound and malic acid (UM) leads to the decrease of the viscosity values and H, as well as the improvement of swelling power, water holding capacity, and oil absorption rate. In addition, scanning electron microscopy (SEM) microgram shows that UM results in the damage and degradation of starch granules. Laser diffraction analysis indicates that native starch and modified starches all exhibit bimodal distribution, and ultrasound leads to the decrease of starch particle size, while malic acid results in the increase. The FT-IR spectra suggest that UM changes the peak intensity and width of starch molecules and produces a new characteristic peak at 1741 cm −1 . In conclusion, UM is effective for modifying starch, and it can promote the taro starch process.