The present invention provides a noise reduction method and apparatus for use in reducing noise of a digital image. The noise reduction apparatus comprises a threshold value generating unit, a determining unit, and an adjusting unit. The threshold value generating unit generates a noise threshold value according to a target window and a first chrominance value and a second chrominance value of an input pixel of the image. The determining unit determines whether the input pixel needs to be adjusted according to the noise threshold value and pixel values of neighboring pixels of the input pixel. The adjusting unit adjusts the pixel value of the input pixel when the input pixel is determined as needing to be adjusted. Using the noise reduction apparatus of the present invention, not only noise of a digital image can be identified, but also the degradation caused by the noise can be reduced and thus the overall picture quality can be improved.