An accurate and broad-band method for heterojunction bipolar transistors (HBT) small-signal model parameters-extraction is presented in this paper. An equivalent circuit for the HBT under a forward-bias condition is proposed for extraction of access resistance and parasitic inductance.This method differs from previous ones by extracting the equivalent circuit parameters without using special test structure or global numerical optimization techniques. The main advantage of this method is that a unique and physically meaningful set of intrinsic parameters is extracted from impedance and admittance representation of the measured S-parameters in the frequency range of 1-12 GHz under different bias conditions. The method yields a deviation of less than 5 % between measured and modeled S-parameters.