The frequency response of Moving Target Indication(MTI) filter is an important indicator to evaluate the performance of radars, which affects the abilities for the receivers to process the echo signals at different speeds. According to the difference between the theoretical model and practical testing, the effects of thermal noise and A/D quantization noise on the frequency response are analyzed in this thesis, then, how the maximal attenuation and the minimal resolving frequency change with these noises is discussed. The conclusion is drawn and validated by simulation.