Abstract: By monitoring and analysis of the elastic wave which appears as gas flows and gas shocks in coal and rock,it is possible to forecast coal's stress state and to locate the source of stress concentration so that to achieve the outburst forecast of coal and gas in advance.With SOS microseismic(MS) monitoring system,the outburst of coal and gas happened at No.1026 working face in the conveyor roadway of Haizi mine on April 25 was measured on-site.The achieved results are as follows.Three indexes were proposed for outburst forecasting of coal and gas that were seismic energy and seismic frequency,seismicity S and total fault area A(t).After seismic energy and frequency increased dramatically,seismicity enhanced and total fault area appeared abnormal high value,coal and gas outburst would happen.Basis and experience were proposed for outburst forecasting of coal and gas by the above three indexes.