In this paper, We proposed a robust blind digital watermarking algorithm using variance and DCT domain. The proposed method embedded watermark signals into DC components of $8{ imes}8$ block DCT using valiance, texture regions and smooth regions. In the digital watermarking algorithms using DCT domain, more robustness can be achieved if watermarks are embedded in DC components since DC components have much larger perceptual capacity than AC components. Experiment showed that robustness of the proposed method better than that of the conventional methods in JPEG quality and scaling attack.