Abstract：The technology of real-time microseism monitoring in the operation-involved area of oil field is an interesting research topic. Some feasible standards and methods about discerning microseism signals are put forward and reliable observation results are obtained in several cases around the world. The observation systems and softwares are developed independently in this research according to the international experience，methods and standards，and satisfactory results are obtained with this methodology in the practices in Daqing，Huabei and Zhongyuan oil fields，China. With microseism observation of flood front at well J430 in fault block J11 of Huabei oil field as an example，the theory and method of observation and discernment criterion are introduced，and the feasibility of this methodology to obtain information about stress state and tectonics at great depth is proved.
