A 0.6-V low-power VCO by using TSMC 0.18-μm CMOS process has been proposed. For lowering phase noise, injection-locked enhancement and bulk-driven technologies are proposed. The injection-locked enhancement technology reuses second order harmonic signals of the oscillation signals through the injection-locked capacitors with the enhancement circuit. The buck-driven technology provides extra transconductance for the cross-coupled pair. The proposed technologies can enlarge the fundamental signal power of the oscillation signals for lowering the phase noise. The measured results show the phase noise at 1 MHz offset frequency from the carrier signal is -118.16 dBc/Hz with 1/f3 corner frequency of 23 kHz while the control voltage is 0.6 V. The frequency tuning range is from 2.33 to 2.37 GHz under power consumption 1.3 mW. The figure of merit at 1 MHz offset frequency from the carrier signal is -184.43 dBc/Hz.