This paper proposes a temperature sensing voltage-controlled oscillator (VCO) with bandgap reference voltage circuit (BGRV) for applications to low power management and wireless systems integrated circuits. This CMOS bandgap core reference voltage makes use of linear combination of PTAT current and BJT VBE to generate bandgap reference voltage source. And this PTAT voltage is to control voltage-controlled oscillator (VCO) output frequency linear change with temperature. This proposed temperature sensing CMOS VCO with BGVR circuit is design and implemented using the TSMC 0.35µm 2P4M process technology. Based on simulated and measured results, the chip size is 0.750×0.641mm2 with power dissipation about 4.285mW, and the operation temperature range from 0°C to 100°C with temperature coefficient about 11.14ppm/°C. The chip supply voltage can from 1.9V to 3.3V operation normally, and its output reference voltage can stable at 1.15V. The VCO control voltage which linearly varies from 1.75V to 2.06V from 25°C to 70°C, and the output frequency linearly varies from 15MHz to 26MHz.