In the present paper, an analysis the data of the M_s=6.0 earthquake Haicheng, Liaoning Province on May 18,1978. has shown that the shock is a new fracture than stick-slip on the seismic M_s=7.3 fault surface.
On the basis of after-shocks data and some formulas of fracture mechanics, we estimated that the total energy of the earthquake is E=6.1×10²¹ergs; seismic moment magnitude is M_o=2.8×10²⁵ dyne. cm and stress decreased to △o=113 bars. Besides, the occurence of the strong earthquake(M_s=7.3) has been conjectured in accordance with the aftershock division of earthguake (M_s=7.3) and the space variation of the level correlative variable caused by the quakes.