The space-time variation of the parameter of attenuation Q-Coda in a sector of the Piedemonte L1anero was studied using the Coda waves. The estimation ofthe attenuation of the amplitude of coda is calculated by means of the Model of simple Isotropic. Dispersion of Sa to, from earthquakes seismograms happened in the region from September 1993 to June 2002. Following the methodology used by Aki and Chouet (1975), they analyzed seismograms in four centered bands to 1.5,3,6 and 12 Hertz with its corresponding bandwidths of 1, 2, 4 and 8 Hertz. And by regression to linear calculated the value of Qc to I Hertz. From the expression proposed by Puli to model the amplitude of the waves coda by means of ellipses, this expression was extended to calculate the space variation ofthe Qc-I, (anelastic tomography). And by inverse square minimums, the value of attenuation for each cell of the three-dimensional model was calculated. Their results were correlated with the regional tectonic frame showing that when the attenuation increases by depth, it corresponds to zones with Tectonics of thick skin and, on the contrary, where the attenuation diminishes by depth, it corresponds to zones with Tectonics of thin skin. On the other hand, the temporary variation of minimum values ofQc (maximum attenuations) was correlated to qualitatively earthquakes of magnitude greater to 3,5 and, in addition, the temporary distribution ofQc was quantified by dimension fractal showing that the grouping of the minimum values ofQc increases before ocurring a main event and its grouping decreases after occurring the main event.