Abstract: Based on the undulatory character of microearthquakes' monthly frequency curves recorded by 8 seismostations in Handan Telemetered Seismic Network,its relation with seismicity of moderately strong earthquakes in North China is studied.The network can provide reliable information of earthquake situation for the dynamic tracing and monitoring to mid and short term earthquakes' tendency in North China.The physical meaning of the data selected and the method to abstract information are related.That the network has the function to reflect the earthquake situation in North China may be relevant to its position,which situates in the joint of the northeast and northwest tectonic zone.This position is most sensitive to the strong and weak variation of stress field.Thus the confidence level of the network to reflect seismic information is relatively high.