A method to improve quality factor (Q) value of inductor is presented in this paper. A negative impedance circuit (NIC) is employed to reduce parasitic resistances and parasitic capacitances of oxide layer and silicon substrate. Simulation results show that the inductor with NIC can improve Q up to 23.1% compared to the inductor without NIC. In frequency range from 2GHz to 6GHz, Q is improved significantly. Moreover, unconsidered reduction in self-resonant frequency of the inductor is also observed.