Seismic quality factor is one of the most useful parameters to describing the attenuation of seismic waves . To calculate the attenuation, the seismic quality coefficient is used which is one of the important parameters of earthquake science. Attenuation is one of the basic parameters in predicting the amount of land movement in the discussion of seismic hazard analysis. The inverse of quality factor represents the attenuation . The attenuation of seismic waves inside the earth consists of two parts of the scattering and intrinsic absorption, and is associated with the seismicity and tectonic complexity of each region, and the quality factor is expressed as a inverse. The studied area is south of Iran . In this research, the least squares method was used to estimate the shear wave quality coefficient. According to the results, the coefficient of quality and frequency dependence of the region for the horizontal component and the vertical component are. The values of the quality coefficients in the reference frequency are 1 Hz and less than 200 . Given the fact that the coefficient of quality and frequency dependency are related to the tectonic conditions of each region, the low quality factor indicates that the area is tectonic in terms of active areas and the rate of attenuation of high waves.