Basing on theory of coal spontaneous combustion,this paper analyzes the coal spontaneous combustion occurrence zone in fully mechanized caving face,and puts forward the "U"-sharp-area of spontaneous combustion in gob.The three zones easy-combustion are redivided into strong permeate zone,weak permeate zone and suffocative zone according to the degree of strength of air flow.Moreover,a new concept "easy-firing area" is proposed on the basis of high-rate spontaneous combustion characteristic in the cross of "U"-sharp-area and weak permeate zone.Technical measures are given for fireproof in fully mechanized caving face in the future accordingly.