42 cases of hyperthyroidism had been operated from 1990-1993.In the preoperative treatment,antithyroid drugs were used togather with thyroxine.Some advantages have been observed,which are better than drugs were used togather with thyroxine.Some advantages have been observed,which are better than thoes of the usual preoperative preparaton.①Patient can be prepared to a complete euthyroid state.②The vascularity of the gland can be reduced to a least degree so that the operative risk of bleeding is will small.③The serum thyroid hormone will not be raised,therefore no thyroid crisis occurs.