Here, we describe a heterojunction bipolar transistor (HBT) voltage-controlled oscillator (VCO) showing extremely low frequency drift with temperature using a compensation capacitor CCO across the base-collector electrodes. CCO has a 5~10 times value of junction capacitor and it efficiently shields resonance frequency stability from junction capacitance fluctuation with temperature. Taking advantage of the added capacitor CCO, we can use smaller capacitors to implement the Clapp-like structure oscillator with a compact layout. Fabricated with 2μm GaAs HBT technology, the oscillator achieves a frequency drift rate < 0.6MHz/℃ and >8dBm output power in 2.5-7.2GHz output frequency band. Excellent 2nd harmonics suppression <-30dBc and superior phase noise of -87dBc/Hz@10KHz and -105dBc/Hz@100KHz are observed at room temperature.