The study of seismicity of the tectonic zone of Kopeh Dagh with the aim of evaluating the seismic parameters of the region in terms of time and place based on the Gutenberg-Richter rule is on the agenda of this research. The catalog of instrumental earthquakes used in this study is based on information published from national and international sources, including 1122 earthquakes with magnitude 3<m <6. The completeness magnitude (mc) is calculated by using the least squares algorithm. The value of mc varies in different time windows, which indicates the non-uniformity of seismic data set recorded in seismic networks in different time intervals. Considering the stable mc determined in this catalog (mc = 4.2), the value of seismicity parameter (b) is less than one, which considering the magnitude of earthquakes in the region indicates the median seismicity in the region.