Scaling of earthquake faults is important not only for earthquake physics but also seismic hazard assessment. There have been many studies about this topic. It is significant to compile, review, and discuss those studies. This work reviews the observations and modeling of scaling of fault parameters, including the fault length (L), fault width (W), fault area (A), average displacement (Do), maximum displacement (Dmax), seismic moment (Mo), and static stress drop (Δσ). Major issues for reviewing in this work are: (1) assumptions of constant Δσ, of earthquakes and self-similarity of faults; (2) the L- and W-models; (3) the L-Do and L-Dmax scaling relationships; (4) the Mo-Do and Mo-Dmax scaling relationships; (5) the Do-A scaling relationships; (6) the Mo-A scaling relationships; (7) the L-W scaling relationship; (8) the Mo-L, and Mo-W scaling relationships; and (9) modeling of the Mo-L scaling based on the one-dimensional spring-slider model in the presence of velocity-weakening friction.