Abstract:Ultrasound and malic acid were applied to modification of taro starch with taro starch as raw materi－ als. X-ray diffraction was used to determine the crystal structure of synthetic product， simultaneously thermal properties，solubility and retrogradation were analyzed. The results showed that the starch which modified in dif－ ferent treatments still kept the original crystal structure， however， their peak intensity of diffraction character－ istics were obviously weakened， showing a decline of crystal lattice ordering degree in starch interior. Compared with native starch， the Te-To values， solubility and retrogradation of starch decreased after different treatments. The Te-To value of starch modified with ultrasound was the highest and showed an increase 26.04 % than origi－ nal starch； Under the action of ultrasound and malic acid， the solubility of modified starch was the best， which increased 300.00 % than native starch and exhibited a raise of 25.82 % than modified starch with malic acid， as a result， ultrasound obviously accelerates the acid-modification of taro starch. The retrogradation of starch mod ified under the combination of ultrasound and malic acid was the strongest and anti -retrogradation was the weakest.