Abstract: Traditional method about micro-seismic monitoring and forecasting always use the micro-seismic events number, frequency and so on, cannot judge on the event itself. Based on previous studies, and refer from the natural seismic energy theory, this paper introduced a new source energy theory to establish the equation about micro-seismic and source energy, and expressed the micro-seismic source energy by explosives equivalent. We can obtain the relationship of magnitude, source energy and explosive charge. And according to the focal point micro-seismic energy, it can derive mine earthquake magnitude. Field studies have shown that, this method can be effectively applied to micro-seismic monitoring and forecasting.