Abstract: The effect of Xanthan gum on the viscosity,freeze- thaw stability and the rheological properties of cationic and anionic tapioca starch were studied by using a Bradender viscometer and a Haake rheometer in the present work.The results showed that the addition of Xanthan Gum increased the peak viscosity,breakdown value for two kinds of cationic and anionic tapioca starch,but decreased their pasting temperature. The syneresis of cationic tapioca starch paste was increased to a certain extent,which reduced freeze- thaw stability. However,Xanthan Gum decreased the syneresis of anionic tapioca starch.After Xanthan Gum was added,the tanα value of two kinds of cationic and anionic tapioca starch gel decreased,energy storage modulus( G') increased,which made cationic and anionic tapioca starch paste became more solid- like characteristics.