A large number of strong ground motion recordings have been collected by the National Strong-Motion Observation Network System of China in the Lushan earthquake sequences after April 0,4. In order to estimate the source parameters of the Lushan aftershocks and the attenuation characteristic of the seismic waves, this study selected 179 acceleration recordings obtained from 15 strong motion stations in 30 aftershocks to estimate the displacement source spectrum and quality factor, based on the generalized inversion technique of the S-wave Fourier amplitude spectrum with one aftershock as the reference event. Various source parameters are estimated by using grid searching technique for each event on the basis of displacement source spectra. It is shown that the average stress drop is slightly lower in Lushan earthquake than that in Wenchuan earthquake. Stress drop is significantly independent on the magnitude, while the apparent stress and the stress drop have favorable positive correlation. The frequency-dependent quality factor Q(f) in this region is found to be 31.867f1.037 5 with the frequency ranging from 0.5 to 20 Hz, the seismic wave attenuates quite faster in Lushan region.