The invention provides a clock generating apparatus, a method for the clock generating apparatus, and a fractional frequency divider. The clock generating apparatus includes an oscillator and a frequency synthesizer. The oscillator is utilized for generating a reference clock signal. The frequency synthesizer is coupled to the oscillator and utilized for synthesizing a target clock signal in accordance with the reference clock signal and a frequency division factor that has been adjusted or compensated, and outputting the target clock signal as an output of the clock generating apparatus. The clock generating apparatus can achieve high frequency accuracy and good anti-shake effect at the same time.