Based on the analysis of traditional ring oscillators, and a high precision and low temperature coefficient oscillator with switched-capacitor is proposed. A frequency based negative feedback circuit with switched capacitor circuit was designed for the oscillator, in which the precision and the temperature coefficient of output frequency was only dependent on external resistor and integrated capacitor. With an appropriate chosen external resistor, a high precision clock with low temperature coefficient could be achieved. The circuit was designed and implemented in a 06 μm standard CMOS process. The simulation results show that the frequency error is less than 174% and the frequency drift over temperature is less than 811×10-5/℃ when the output frequency is 5 MHz.