Abstract: Integrated Inductors on silicon were designed and fabricated,and a method was applied to reduce the silicon substrate eddy currents. The method to form the p-n junction isolation in the Si substrate can be realized in standard silicon technologies without additional processing steps. S para- meters of the inductors were investigated based on equivalent circuit. Experimental results show that substrate p-n junction isolation at certain depth achieves good improvement may increase the in- ductor quality factor up to 40%.