Abstrac
In this study, the quality factor of coda waves (Qc) due to its importance in earthquake engineering and population density, high seismicity, the presence of gas reserves and important industrial centers, in the east and northeast of the country based on Single Back-Scattering method and using multi-station model and Calculated using 166 events. The initial database consisting of 300 earthquakes with a magnitude of 2.5-6 ML was merged of waveforms recorded in three seismic centers of the country, including the National Seismological Center of the University of Tehran, the Broadband Seismic Network of Ferdowsi University of Mashhad and the National Center of Broadband Seismic Network of Iran. The relationship between quality factor for the east and northeast of Iran is equal to QC = 125f0.76. The calculated QC value is in line with the seismicity, east and northeast of the country, and indicates high seismicity and high attenuation in this area.