Firstly,an image analysis method,namely integral optical density ( IOD) method,was combined with the model of response difference of crystallite change ( MRDCC) to analyze the gelatinization property of Chinese yam starch.Then,XRD was adopted to discuss the crystalline structure of the starch.Finally,the effects of concentration and sugars variety on the gelatinization process were analyzed.The results demonstrate that ( 1) Chinese yam starch is in a C-type structure; ( 2) MRDCC shows double peaks that correspond to the gelatinization process of types B and A paramorph; ( 3) different sucrose concentrations as well as various monosaccharide,disaccharide,trisaccharide and tetrasccharide have different effects on the gelatinization process; ( 4) the inhibition effect due to sugar shows good correlation with dynamic hydration number,concretely,the more the equatorial hydroxyl number ( e-( OH) ) of sugar molecules,the stronger the inhibition effect; ( 5) sugar-water hydration effect is also related to the size and three-dimension structure of sugar molecules; and ( 6) a helical structure bonded through hydrogen bond is ideal for tetrasccharide because this structure weakens the hydratability,which means that the gelatinization inhibitiion effect of stachyose is smaller than that of raffinose.