Abstract:Based on the earthquake catalogues of the Liaocheng-Lankao fault zone and the 50 km surrounding areas since 1970, combined with historical earthquake and seismic background data, we calculate the b-values and point out the highest stress accumulation areas. We use the maximum likelihood and the least square methods, then utilize probability of seismic potential method on north and south segments to calculate the time-dependent seismic potential probability and the background seismicity. We make following conclusions: (1) Fanxian, Qingfeng, Puyang and Juancheng are in high stress accumulation areas, with stable b-values ranging 0.6~0.7.(2) Depending on the time-dependent seismic potential probability, the south of Liaocheng-Lankao fault zone will be more dangerous in the next 50 years and all fault zones will have higher probability of M5.0~6.0 earthquakes occurringin 100 years. (3) The earthquakes in the study areas are mainly concentrated in 115.2°to 115.6°E, 34.9°to 36°N, and the seismicity made greater change more since 2000.