Abstract: Most of moderate strong shocks occur in active fault belt.It is important to stu-dy stress state of these seismic belt and temporal-spatial characteristic of earthquakes in the belt for exploring precursor information before large shock.Based on analysis of seismicity in seismic area before M≥6 earthquake in North China since 1970, it is shown that spatial distribution of moderate and micro-earthquakes trends to converge-nce towards the belt in 2-3 years before large shocks, and diverge outward belt in 1-2 seasons before shock.The tendency provides some information for earthquake prediction.