This paper proposes a meaningful digital watermarking algorithm for remote sensing image based on DCT and fractal theory. Firstly, it determines self-similar blocks for watermark embedding by using fractal technology, then scrambles the watermark with Arnold transformation and the scrambled watermark image next be scanned into one-dimensional sequence, at last it applies DCT to the selected self-similar blocks and embedds the watermark into the blocks. Experiments have shown that the algorithm proposed in this paper has good invisibility, simple calculation, easy realization, and extracting watermark without the original remote sensing image. And it is well robust against JEPG compression, filtering and noise superimposed attacking.