Abstract: In order to investigate the seam deposition conditions of No.101 mining block in Qinan Mine, based on the geological exploration and the systematic ana lysis and statistics of the mining conditions, a fractal theory was applied to the complexity evaluation on the geological structure corck network of No.101 mining block a nd to discuss the relativity between the deformation coefficient of the folding plane and the corck fractal dimension value.The study results showed the complexity degre e of the corck structures in the middle of the west part and the north east part of the mining block would be complicated to very complicated mainly and the complexity d egree of the fracture structures in the north west and south east area of the mining block would be simple to medium.The comparison study was conducted on the relati onship between the deformation coefficient of fold plane and the crack fractal dimension within the mining block. The deformation coefficient of fold plane in the middle 0 f the west and the northeast of the mining block was high, the fractal dimension of the crack structure was increased, the deformation coefficient of fold plane in the nort hwest and southeast parts of the mining block was small, the fractal dimension of the crack structure also was small and the variation tendency of the above two coeffici ent would have certain relevance.