An accurate and simple method to extract equivalent circuit parameters of fully-depleted silicon-on-insulator MOSFETs small-signal modeling operating at RF frequencies including the non-quasi static effects is presented in this article. The advantage of this method is that a unique and physically meaningful set of intrinsic equivalent circuit parameters is extracted by de-embedding procedure of extrinsic elements such as parasitic capacitances and resistances of MOSFETs from measured S-parameters using simple Z- and Y- matrices calculations. The calculated small-signal parameters using the presented extraction method give modeled Y-parameters which are in good agreement with the measured Y-parameters from 0.5 to 20GHz.