Experiments on the variations in apparent resistivity in the rock walls of the underground mine tunnels had been made for more them two years, meanwhile the stress-strain state of the walls was changing with adjoining tunnels being dug.
This papev presents and analyses the obtained data in detail, which include those of stress, strain, apparent resistivity, and so on, The mechanism on variations of apparent resistivity and the problem about the directins of extreme values of the variations are discussed briefly.