Abstract: KM mice were fed with various dose iodine containing diet for 1 week, and then, injected into 37 MBq  99 Tc mO - 4,  99 Tc m uptake were mearsured at different time, the main aim is to study the effects of high Iodine containing diet on  99 Tc m uptake of thyroid.  99 Tc m uptake were mearsured at the different time. Contrast analysis of the date were done by the Dunnett t test and SNK q test. Compared with the control group, the significant differences were found at different time between high iodine containing and normal diet groups at the time of 10, 20 and 60 min（ t _{1,0（ 10 min）} =7.364， t _{2,0（ 10 min）} =6.807， t _{3,0（ 10 min）} =6.674， t _{4,0（ 10 min）} =5.594； t _{1,0（ 20 min）} =9.843， t _{2,0（ 20 min）} = 9.730， t _{3,0（ 20 min）} =9.132， t _{4,0（ 20 min）} =9.128； t _{1,0（ 60 min）} =5.958， t _{2,0（ 60 min）} =8.292， t _{3,0（ 60 min）} =8.147， t _{4,0（ 60 min）} = 6.358 P＜ 0.01）. But at the time of 30 min, there is no significant difference for  99 Tc mO - 4 uptake between the control group and the high iodine containing diet group. All the results show that high iodine containing diet depressed the function of  99 Tc mO - 4 uptake in the thyoid of mice. 