We performed time-resolved X-ray diffraction for laser-irradiated Si(1 1 1) single crystal. A tabletop TW laser system was used for the generation of the ultra-short pulsed X-rays. We discussed the generation of laser induced ultra-short pulsed X-rays concerning about broadening of diffracted signal due to the electron scattering in the pre-plasma. We measured laser induced acoustic wave propagation inside of Si crystal by the laser irradiation, and the maximum lattice strain of -1.05% was measured at the irradiation power density of 4.7 x 10(9) W/cm(2) with picosecond time resolution. Stress distribution analysis on the observed data under laser irradiation is also discussed. (C) 2002 Elsevier Science B.V All rights reserved.