The software package (SP) Coda Q for the medium Q-factor computation on the basis of single scattering model was developed. It allows preparation, verification and processing of local earthquakes records by the prescribed algorithm. SP was used for the Q-factor computation on the territory of North Tian-Shan on the basis of   on the territory explored for the period 1999-2012. For every station the function of Q-factor – frequency dependence (Qc(f) = Q0 · fn) mode was received. The results obtained are used for attenuation function development,which is engaged in focus spectrum generation, which, in turn, for computation of earthquake dynamic parameters isused.