Acoustic emission as a method of measuring ground stresses has aroused increasing interset. Rock has the function of "memory" of its stress history.By using this function, the authors applied acoustic emission to the analysis of rock samples from the Dongying subbasin and obtained the ground stress memory values and memory occurrence rates and thus further revealed the phase number and intensity of tectonic activities that this area underwent.The results of the measurements demonstrate that the paleo-stress memory values coincide with the stress history in the tectonic cycles.Furthermore, the paper briefly introduces the basic principle of acoustic emission.