A capacitance interface circuit is provided. An external inductive capacitor is divided into a variable portion and an invariable portion. The capacitance of an internal adjustable capacitor is designed to be equal or close to the fixed capacitance of the external inductive capacitor. The internal adjustable capacitor is used for storing charges having a polarity opposite to that of the invariable portion of the external inductive capacitor in order to neutralize the effect of the invariable portion of the external inductive capacitor. Thus, a charge converter composed of a fully-differential amplifier and feedback capacitors needs only work on the variable portion of the external inductive capacitor, and accordingly the accuracy in subsequent data processing is increased.