This paper proposed a dual-core quad-mode with re-configurable magnetic coupling mode and negative-resistive mode switch VCO implemented with 65nm CMOS technology. By switching the Even_SW, Odd_SW, SW1, and SW2, the VCO can operate in a different magnetic coupling coefficient Mode causing different oscillation frequency bands. A post-simulation shows the way reconfiguring the coupling coefficient can improve the tuning range up to 91.8% and consume about 15mW achieving the best FoM and FoM T of 185dBc/Hz and 203.3dBc/Hz respectively. Besides the negative-resistive mode switch is proposed to break the trade-off between the parasitic capacitor and phase noise of traditional positive-resistive switch without mode ambiguity.