Abstract: Taking monitoring for the coal production and boreholes for scientific research as subject，cases for boreholes of stress measurement are analyzed.According to the Kirsch derivation results，it is determined that the selected drilling diameter should not be greater than the permission.The calculation results indicates that the range of drilling hole diameter are mainly affected by factors of stress state of borehole，the mechanical properties of the surrounding rock and installation conditions，so as to propose the principle of selecting drilling parameters.At the same time，the selection of drilling parameters provides a theoretical reference for research and development of other monitoring devices and the equipment and instruments for scientific research.

Key words: Drilling diameter, Drilling stress meter, Allowable drilling diameter