Abstract: In the process of deformation or cracking damage of rock and other media under external force，the elastic energy may release to generate microseismic events.Microseismic monitoring system based on optical fiber sensing technology adopting optical fiber grating acceleration sensors，which is not affected by light intensity in the process of signal transmission，has long distance transmission，intrinsic safety，anti-electromagnetic interference and overcome the shortcomings of traditional electronic microseismic sensors.To verify the system performance，the plane vibration monitoring experimental was carried out，and the least square method was used to achieve microseismic source plane location.Experimental acquired clear waveform，high signal to noise ratio，high damping，the location precision is greatly improved when sensors are arranged around the source.Microseismic source location error isn't decreasing with the increasing of the sampling frequency.This experiment is an important reference for optical fiber sensing microseismic monitoring system used in the rock burst monitoring in coal mine.

Key words: Microseismic, Optical fiber sensor, Plane location, Least square method, Sampling frequency