Abstract: Based on the microscopic-analysis on casting thin sections,SEM,X-ray diffraction and cathodoluminescence,the author believes that the silicic cementation is the dominant cause for the reduction of a large amount of pores in Ed¹ reservoir and the poor effects from acidization procedures for production improveme.Therefore,it is proposed that hydrofluoric acidizing process should be adopted on the reservoirs with well-developed silicic cementation when the acidization procedure are applied to oil/gas development,which does show good effects.