The　surface　shape　and　microstructure　of　images,　especially　digital　images,　have　important　influence　to　construct　characteristics　such　as　analysis,　transformation　and　compression　into　digital　images,　etc.　The　main　purpose　of　this　paper　is　to　use　the　fractal　dimension　and　multifractal　spectra　to　analyze　the　characteristics　of　digital　images.　We　will　first　give　a　brief　description　of　Fractal　Theory　and　then,　the　characteristic　analysis　of　digital　images.　Based　on　box-counting　method,　an　algorithm　is　derived　to　calculate　the　fractal　dimension　and　multifractal　spectra　of　digital　images.　Then,　a　computing　program　of　the　fractal　dimension　and　multifractal　spectra　is　developed　with　the　help　of　MATLAB.　Through　this　program,　the　surface　shape　and　microstructure　of　digital　images　are　described.　The　results　of　this　study　developed　an　effective　tool　to　analyze　the　surface　characteristics　of　digital　images.　©　2012　American　Scientific　Publishers　All　rights　reserved.