This paper presents the realization of tunable grounded and floating immittance simulators using current transfer functions. The proposed circuits are composed of some second-generation current conveyors (CCIIs) and operational transconductance amplifiers (OTAs). Choosing the appropriate output, the circuits can realize high-pass, band-pass, and low-pass immittances, and the immittances can be tuned by adjusting the amplifier bias current (Iabc) of OTAs. Two examples are shown together with simulation resulted by HSPICE.