By using the computer image processing and analysis, a system to detect the weave pattern and yarn colors was developed under Windows 3.1. The image of woven fabric was captured by a HITACHI color CCD camera and converted into digital data through TARGA+32 board. To determine the weave pattern, the changes of gray values at warp/weft interlacing position were analyzed. And this method can also be adapted to colored and patterned fabrics. To do this, the two images, i. e., the transmissive and reflective illuminated images, were used. From the transmitted image, the informations about yarn positions were analyzed. And from the reflected image, the warp/weft interlacing data and the arrangement of colored yarns were obtained. By analyzing the aspect ratio of ellipsoidal image at warp/weft interlacing positions, the warp/weft interlacing data could be obtained. And the HSV color model was used to classify the same yarn colors.