In this paper, a new CMOS realization of Current Differencing Current Conveyor (CDCC) is proposed. Furthermore, to demonstrate the performance of the CMOS circuit, a new biquad filter configuration is introduced employing a single CDCC and four passive components. The proposed filter has three-inputs, a singleoutput and realizes current-mode low-pass, band-pass, high-pass, and band-stop filter functions. The biquad filters realizing these filter functions are simulated using TSMC CMOS 0.35 mu m technology. PSPICE simulation results agree well with the theoretical analysis.