An ultra low power dissipation voltage reference based on subthreshold without resistors and BJT was presented. An Oguey current reference source was used to reduce the static current, and an operational amplifier working in subthreshold region was used to significantly increase the power supply rejection ratio (PSRR) with low power consumption. The two different threshold voltages of 1.8 V and 3.3 V MOSFETs were used to get a smaller temperature coefficient. A cascode current mirror was used to increase the PSRR and reduce the line sensitivity of the circuit. The voltage reference was designed and simulated in SMIC 0.18-μm CMOS process. The simulating results for the voltage reference demonstrated that the temperature coefficient of the voltage was 9.3×10－6 /℃ at the temperature range of -30℃ to 125℃. The line sensitivity was 0.16% at the supply voltage range of 0.8 V to 3.3 V, and the PSRR was -58.2 dB at 100 Hz. The power dissipation was only 109 nW, and the chip area was 0.01 mm².