Abstract: According to Mining regulation under buildings, water body, railway, Practice has proved that the empirical formula for height of water conducted fracture d zone in has been unable to fully meet the requirements for fully mechanized mining.In order to obtain more reliable empirical formulas, this paper collected a large nu mber of domestic statistical data measured at different overburden strata conditions, fully considering the effect of mining thickness, mining depth, coal seam dip, work f ace length, and analysed the data by using the powerful SAS mathematical software.By comparing the results of different methods, this paper summarized that the emp irical formula for height of water conducted fractured zone in under buildings, water, railway had large error at the conditions for fully mechanized mining.Choosing the p recise empirical formula under the condition of fully mechanized mining had a guiding significance for the engineering practice.