Abstract: Ownership evidence can be directly exposed through visible watermarks which can avoid the attempts of copyright abuses. JPEG images are widely used for many commercial applications in Internet, because of its reduced size and the requirement of low bandwidth. In this paper, a visible watermarking scheme is proposed for JPEG compressed images. This scheme is based on the modification of frequency coefficients of original image with respect to the frequency coefficients of watermark image. In JPEG compression, forward discrete cosine transform (DCT) phase is processed to embed visible watermarks. Different sizes of color and grayscale watermark images can be embedded in the carrier image with high visibility. Experimental results confirm the quality of the proposed visible watermarking scheme.