this work is to evaluate the performance of the Greater Cairo seismological network through the probability of magnitude detection in this region, adopting the probability-based magnitude of completeness method. This method was already applied to the largest seismic network in the Middle East which is the Saudi National Seismic Network (SNSN) and also to the Oman Seismic network, but this is the first study of the earthquake detection capability in Egypt. To implement this method of work: the use of the spatial configurations of seismological network, the phases of recording data and the magnitude equation are construct the all needs. The historical data and current configurations of each station in this region are saved with document. The scrutiny is done on the magnitude of an earthquake database for all events in the period of January 2018 to December 2020. The method is applied to calculate the probability of the detection capability on each seismic station, which is then combined into maps resulting from these calculations for events with certain magnitudes. These maps clarify that the Greater Cairo Seismic Network of station is already able to record successfully small earthquakes and nearest regions for this detection. The probability of the magnitude of completeness plot indicates that most earthquakes generated with a strength magnitude equal to or greater than ML 2.5 are completely recorded. Nonetheless, the results displayed clearly that adding some observatory stations will enhance the detectability of humankind and naturalist small earthquakes at certain regions around the Greater Cairo Region.