Abstract： Objectives To assess the effect and Security of "Sandwich" therapy in treating staghom calculi.Methods We retrospectively investigated the patients Clinical data of staghorn calculi.Results Of 109 cases,calculi within bilaterall horseshoe kidneys was 2.50 patients were rendered stone free at 1 session with percutaneous nephrolithotomy while 52 patients through the "sandwich" therapy.No major complications were seen.Conclusions "Sandwich" therapy is a safe and effective method of treating staghorn calculi.