Abstract: On the basis of available data mainly from seismic sounding crustal structures in North China are held to be characteristic of 1) vertically layered crust,consisting of upper,middle and lower crust,the reverse of seismic velocity occurs in the middle layer as shown on the seismic profiles;2) the lateral inhomogeneity and discontinuity on the Moho,sharp abruption of the velocity often points to the peaks of the Moho relief.Comprehensive analyses have been made for earthquake-generating structures in de-ep earth,geothermal activity and motion of deep-seated substances.