Seismic tomography is a new geophysical technique being developed to meet the needs of mining and engineering projects. Attenuation tomography, as one kind of seismic tomography technique, is a powerful prospecting tool for determining structure defaults such as fault, broken zone, and hidden voids, but it has been little discussed up to now. Its principle and applications are presented in detail. Attenuation tomography technology includes the following main points. First, on the basis of spectrum analysis to each seismic record, geometric correction is conducted, then common source parameters are introduced into common shot records in order to keep absorption effect of the geological media separate from source spectrum influence. Finally, an equation set is obtained which consists of absorption coefficients, common source parameters and energy field data observed. This technique can be employed together with velocity tomography to provide more evidence for engineering and geological diagnosis. Its applications to exploration of mineral and engineering have led to satisfactory results.