Abstract: The earth stress is the principal factor to vertical frac- ture height.The perfect fracture height shall be equal to that of the target stratum,and the excessive extension of fracture in the vertical direction will engender adverse effects.On the basis of previous studies,presented in the paper are the rela- tionship between the earth stress and the fracture height,the effects of vertically excessive extension of fracture,the rela- tionship between the target stratum and the minimum hori- zontal principal stress of the adjacent stratum,the object of fracture height control,and the fracture height control tech- nique,which is of guiding significance to the fracturing de- sign and the on-site operation.