Resonator Integrated Optic Gyro (R-IOG) adopts advantages of the micro integrated optoelectronic technique, whose ring resonator is fabricated by optical integrated circuit. Polarization fluctuation induced noise is one of the dominant noise sources in resonator. State of polarization (SOP) of the input light, polarization maintaining quality of the coupler and the waveguide and the fluctuation of the temperature are main parameters which affect polarization noise of integrated optical gyro. Through simulations and experiments, three countermeasures are introduced. The first and second are for exciting one polarization mode of the waveguide. The first way is modulating the SOP of the input light utilizing polarization controller or polarizer and the second one is raising polarization maintaining quality of the waveguide through the birefringence caused by residual stress and core size. The third way is increasing the distance of two resonance dips by control the temperature at an appropriate point to fix one resonance dip at the center of the other resonance interval. The polarization noise can be suppressed through the ways mentioned above.