A color information interpolation method is disclosed. The color information interpolation method comprises steps of receiving a luminance information corresponding to a pixel matrix, wherein the luminance information is arranged in a Bayer pattern and records a specific color information of each pixel of the pixel matrix, and the specific color information is one of a red color information, a green color information and a blue color information, calculating a horizontal variance and a vertical variance of a pixel according to the luminance information, and interpolating the pixel of the luminance information with one of a horizontal color estimate, a vertical color estimate and a directionless color estimate according to the horizontal variance and the vertical variance, to derive color information of the pixel other than the specific color information.