Abstract: OJECTIVE To explore the effects of different Preoperative Drugs and the administration time length iodine on thyroid hemodynamics change. METHODS 60 elected cases were randomly divided into two groups, 30 cases in each group.Ⅰgroups: methimazole tablets+propranolol;Ⅱgroup: methimazole tablets+propranolol+levorotatory thyroxine tablets. All cases were examined bilateral the hemodynamic parameters of thyroid ascending and descend artery respectively before and after the usage of iodine 7 d, 10 d, 14 d, and the measurement data were statistically analysed. RESULTS These parameters gradually reduce, within 10 d after taking iodine, and no change (P>0.05) after 10 d inⅠgroup. The thyroid had significantly reduced blood flow after 7 d of drug treatment. The extension of iodine treatment time had no effects on thyroid blood flow (P>0.05) inⅡ group. CONCLUSION Hyperthyroidism preoperative preparation of different drugs on thyroid hemodynamics by color Doppler ultrasonography can be evaluated, methimazole pieces+propranolol+levorotatory thyroxine pieces therapy can shorten preoperative serving iodine time.