Image analysis was applied to evaluate the colors of cotton fabrics dyed with natural and synthetic dyes. Color measurements of these fabrics were done with a commercially available color scanner and a colorimeter. The X, Y, Z, L*, a* and b* values of the CIE color system were obtained for each pixel (i,j) in the image by respective measurements and by appropriate transformation of the values. The colors of the fabrics were measured either vertically or horizontally with a scanner having 512 divisions for every 6.5 cm, with ca. 0.1mm spacing. Total values of L*, a* and b* for all pixels in the vertical direction for pixel position ( i ) in the horizontal direction (i=0~511) were SVi-L*, SVi-a*, and SVi-b*, respectively. Similarly, SHj-L*, SHj-a*, and SHj-b* were also obtained for all pixels in the horizontal direction for pixel position ( j ) in the vertical direction (j=0~511). The SVi-L* and SHj-L* values of fabrics dyed with natural dyes showed large degrees of variation, while those with synthetic dyes showed very small degrees of variation. The difference between the colors of the cotton fabrics dyed with natural and synthetic dyes were discussed in relation to the coefficient of variation.