A total of 160 patients's nontoxic multinodular goitre and graves disease have been operated by the total thyroidectomy at national hospital of endocrinology from 2/2005 to 6/2006. These patients were aranged in 2 groups by random to access the thyroid compartment, for lst group: the authors opend the middle line( traditional approach), for 2nd group: the patients was operated by a lateral approach (by dissection of muscles). The study was based on the anatomy of neck, the changing of the neck's muscles according to the degree of goiter. the comparison between 2 groups has showed: there were no significantly differences about the age, sex, degree of goiter, and the kind of thyroidectomy. In the first group, there were 34 cases(42.5 percent) who have been cut the sternothyroid muscle and the sternohyoid muscle while there was not any case in the second group. The intraoperative difficult dissection was in 27 cases of 1st group and only in 5 cases of 2nd group. The operative time of 2 groups was 83.6 minutes and 94 minutes
the blood loss was 15.3 ml and 13.6 ml, respectively. The temporary hoarseness, hypo calcium were in 7 cases and in 12 cases of 1st group. But, there were only 3 cases and 4 cases of 2nd group. Conclusion: For the thyroidectomy, the lateral approach has some more advantages than the middle approach.