Abstract: Fault is one of the two most basic types of structural element (faults and folds) in lithosphere. The stress state in the lithosphere is discussed, the classic mechanical faulting model, Anderson's faulting model, is introduced, and the limitation of Anderson's model is discussed in the paper. On this basis, a recently proposed mechanical faulting model with pre-existing weakness, i.e., ''non-Andersonian faulting model'', is focused on. In addition, the sandbox modeling verification of this model and its application prospects are introduced.

Key words: fault, Andersons faulting model, pre-existing weakness, lithosphere, non-Andersonian faulting model