Abstract: A concept of general transconductance of V/Q (voltage/charge) transformation i.. proposed, and applied to the simulation of switching capacitance impedance. By Using V/Q transverter, the expected impedance function can be implemented by means of volrage transfer function. Starting from this concept, the switched capacitor-FDNR (frequency dependent negative resistor) circuits of three kinds of S/Z transformation (i.e. forward differential SfZ transformation, backward differential S/Z transformation, bilinear S/Z transformation) are respectively deduced. If the selected voltage transfer function circuit is not sensitive to stray capacitance, then the implemented simulation impedance circuit is also not sensitive to stray capacitance. As an example, a resonant loop is composed of forward differential FDNR circuit. The experiments show that the characteristics of its frequency response coincide with the theoretical analysis.