he time-resolved reflectivity(TRR) technique has been used to measure the solid phase epitaxial growth rate and the thickness of epitaxial layer for Si+ and As+implanted single crystalline wafers.The thickness of amorphous layer for the As-implanted samples has been determined by backscattering-channeling analysis to confirm the measured TRR results.The principle of the TRR technique is introduced and the experimental result is discussed.