A sampling rate adjustment system includes a detecting circuit and a processor. The detecting circuit detects a frequency of an alternating current (AC) power source and outputs a detecting signal. The processor receives the detecting signal of the detecting circuit and determines whether a difference between the frequency of the AC power source and a sampling rate of a camera is less than a predetermined value. The processor outputs a control signal to the camera and changes the sampling rate of the camera when the difference between the frequency of the AC power source and the sampling rate of the camera is less than the predetermined value.