Identification of the components of fifty uri-nary calculi was achieved by the scanning elec-tron microscopy ( SEM ).Preparation of spec-imen requires washing, adequate desiccation and coating. The common components, including calcium phosphate, calcium oxalate, magnesium ammonium phosphate, uric acid and cystines all possess their own distinct morphology through the magnification of SEM and are readily rec-ognized. Even in mixed stones, the minor com-ponents are hardly overlooked. The procedure is easy to apply. The observation of intact archi-tecture of calculi can be easily obtained, regard-less of any size. Undoubtedly, SEM is an excel-lent approach to stone analysis at present.