Abstract: Corneal biomechanics is the science that investigates and analyzes the properties of cornea, such as viscosity resistance and overall resistance. The biomechanical property of corneal is one of the most important factors effecting the predictability and stability of corneal refractive surgery, and which related to the different operative method and ablation depth. For example, lamellar ablation has more effects on corneal resistance than surface ablation. Both corneal hysteresis and corneal resistance factor decrease significantly after thick flap creation. And deeper ablation may result in obvious corneal resistance factor reduction. These changes are highly related to some complications like keratectasia and regression, etc.