An improved LC voltage-controlled oscillator (LC-VCO) with low power consumption and low phase noise at 2.4 GHz oscillation frequency is proposed in this paper. As an optimization scheme, the active MOS transistor devices are employed to replace the passive resistors and capacitors in order to reduce the layout area and power consumption, as well as improve the comprehensive performance of VCO. Based on TSMC 65 nm/ 1.8 V CMOS process, a VCO circuit is designed and simulations are performed for performance analysis. By combining theoretical modeling with small signal equivalence circuit, appropriate parameter tuning is realized for the replacement of key passive devices. The simulation results show that the improved VCO has a tuning range from 2.365 GHz to 2.506 GHz and the tuning bandwidth of 141 MHz, phase noise of -127.272 dBc/Hz@1 MHz, and as low as 1.323 mW power consumption at 1.8 V power supply voltage. Furthermore, the value of figure of metrics(FoM) is up to -193.84 dBc·Hz-1, which is better than most of other same LC-VCOs at the same frequency range.Key words: