Abstract: Extensional fault-propagation fold, an important kind of folds in extensional environment, is formed by propagation of the basement blind normal fault into sedimentary cover which was bent and thinned. The deformation is accommodated by trianglelike upward widening distributional shearing, and the up tip of blind fault controls the position of the apical angle of the shear zone. The tri-shear modeling matched well with the material movement in deforming zone. The apical angle of tri-shear zone and the fault propagation to slip ratio (p/s ratio) are both important parameters controlling the geometry and deformation of the extensional faultpropagation fold. The process of extensional fault-propagation folding can be divided into two stages by whether the blind fault propagates through cover strata. During deposition, extensional fault-propagation folding controls the geometry and superimposed pattern of grow strata strongly. The blind fault nucleation point and propagation amount can be determined exactly by analysis of the geometry of reserved growth strata and the development of extensional fault-propagation fold can be finally restored.