Recently our coal mines have been getting into deeper parts in their extractive zones. Therefore, on account of high rock pressure various troubles have occurred one after another, such as rock burst, sudden outburst gas and coal, etc. In order to obtain predictive and preventive measures of them and to make the relationship clearly between seismic motions and rock destructions, we have taken up seismograph.Generally speaking, just before above mentioned disasters will happen, many ground vibrations are felt propagated from some positions of rocks destruction.Measurements had been performed in Mitsui Sunagawa Colliery during 70 days last year, and following results were aquired.(1) Total amount of data reached 200 ones. All of them oscillative frequencies were below 100Hz.(2) By calculating reaching time of these seismic waves, we got 94 origins of destruction points in the rocks.(Fig. 6)(3) During the measurements, some audible rock noises were recognized at the stope site, and the each time of them, as tabulated in Table 5, was in good correspondence with that on the seismic wave record obtained at the surface station.Further investigation based on this result is expected in order to locate the spot in which the rocks are destructing, and to find the relationship between original positions of rock destruction and extractive zones.It will contribute to prevent underground disasters.