In this paper, we designed a 2-stage CMOS operational amplifier with temperature compensation function using 2-poly 4-metal 0.35 $mu$m standard CMOS technology. Using two bias circuits, the positive temperature coefficient(PTC) and the negative temperature coefficient(NTC) of the bias circuit are canceled out each other. When reference current circuit is simulated that it has a temperature coefficient of -150 ppm/$^{circ}C$ with a temperature change from 0 $^{circ}C$ to 120 $^{circ}C$. Also the proposed circuit has a temperature coefficient of -0.011 dB/$^{circ}C$ of DC open loop gain with the same temperature range.