A method based on Bayer filtering to obtain color images was introduced, then the Modulation Transfer Function (MTF) of a color area Charge Coupled Device (CCD) which uses the Bayer filtering to obtain color images was established based on the discrete sampling characteristic of CCD. The MTF values for the color area CCD using Bayer filtering were compared with those of a monochrome area CCD. Obtained results indicate that the MTF value for color area CCD using Bayer filtering is notably lower than that for the monochrome area CCD. When the side length of a pixel is equal to the corresponding center distance, the MTF value at Nyquist frequency is 0.067 6 for the color area CCD using Bayer filtering while that is 0.405 3 for the monochrome area CCD. Moreover, in an imaging experiment using a resolution card, the resolution of the former is lower about 40% than that of the latter in the same imaging condition. These results are coincident with comparative analysis results of MTFs in general.