Abstract: It is convenient and clear to characterize and identify rough surfaces and debris with fractal parameters of scale independence. The prediction results using fractal models of tribology would not change with the resolution of measuring instruments and the length of sample, so the models are more reasonable and effective than those based on statistical analysis. The current state and the development in the application of fractal geometry to the characterization, contact, wear prediction, frictional temperature distribution of rough surfaces, and debris analysis are reviewed. Several important issues about the application of fractal geometry in tribology are put forward.