The present invention relates to a CMOS image sensor. According to the present invention, the CMOS image sensor includes a two-dimensional pixel array (110), a row decoder (130), and a column decoder (150). The two-dimensional pixel array (110) includes rectangular unit pixels each having a width to length ratio of 1:2. The row decoder (130) is placed on one side of the pixel array to designate a row address. The column decoder (150) is placed on another side of the pixel array to be perpendicular to the row decoder and is adapted to extract data of respective pixels from a row selected by the row decoder, amplify the extracted data and generate image data including pixel values. As a result, the present invention is advantageous in that it can easily perform interpolation compared to an image sensor having regular quadrilateral unit pixels.