The author proposes a new fully integrable Membership Function Circuit (MFC) using a Current Differencing Buffered Amplifier (CDBA) which employs two second generation current conveyor (CCII) and a voltage buffer. This MFC achieves basic membership functions such as trapezoidal, triangle, S-shape, and Z-shape. The characteristics (width, height, and position) of the implemented MFC are easily adjusted by varying left and right voltages and bias currents. Since the proposed MFC is implemented with a single CDBA block with simple structure, it can be capable of high-speed operation and integrated as a circuit to cover small area of a chip. The behaviour of the proposed MFC has been verified by PSPICE using the model parameters with 0.5 mm MIETEC CMOS process. The proposed MFC is voltage-input current-output and CMOS based structure with low supply voltages (+/- 1.5V), Therefore, it is suitable for both current-mode and low-voltage fuzzy and neural hardware.