A high precision voltage regulator was proposed. It can work under the supply voltage from 8V to 20V. Compared with conventional regulators, its performances were improved by boosting the feedback loop gain, minimizing the effect of base width modulation and base current error correction. Simulation results showed the line regulation of 33muV/V and load regulation of 30muV/mA was achieved. And by using a cascode current mirror to shield the core circuit from power supply noise, PSR (power supply rejection) of 120dB at low frequency was also achieved