Abstract: To evaluate monitoring ability of Shanxi seismic network scientifically, taking the seismic observation report produced by Shanxi seismic network as the input, detection probability of 57 stations of Shanxi seismic network to earthquake events surroundings, synthetic detection probability and minimum integrity magnitude of seismic network are calculated by PMC method of integrity magnitude which is based on probability. It is illustrated by detection probability result of single station that PMC method relatively objectively reflects the capability of 57 stations to earthquake events, and that 5 stations in central Shanxi have high detection capability to earthquakes of small magnitude because of large density and reasonable layout of stations and that Stations located near the northern and the southern provincial boundary of Shanxi has relatively weak detection capability. The result of synthetic detection probability shows that the high detection probabilities are mainly concentrated at Xinzhou, Taiyuan, Jinzhong, Linfen and some areas of Datong and Changzhi of Shanxi, which are areas of the most strong monitoring capacity and that earthquakes of M_L1.0 and below can be monitored in 80% regions of Shanxi, and that after sharing 17 stations in the neighboring province, minimum integrity magnitude M_P near the northern and the southern provincial boundary of Shanxi reaches 1.7, whose monitoring capacity is weak, compared to the central region. To improve monitoring capacity of Shanxi seismic network, station density is needed to add in the northern and southern provincial boundary of Shanxi or more stations from the neighboring provinces are introduced to further optimize the station layout of Shanxi seismic network.