[en] Objective: To discuss the influence factors in the evaluation of thyroid mass with thyroid model SPECT imaging. Methods: The thyroid model was filled with ⁹⁹Tc^mO₄^- 74 MBq in water. Then the thyroid static imaging and tomography were performed with the ⁹⁹Tc^mO₄^- filled thyroid model in different acquisition matrixes, zoom settings and present counts. The thyroid masses were evaluated by thyroid static imaging composed with pixel, and by thyroid tomography composed with stereology. The results were compared with each other. Results: The thyroid masses evaluated by pixel increased or decreased in different acquisition matrixes, zoom settings and present counts. The evaluated thyroid mass was most close to the thyroid model's real weight in the condition of 128 x 128 matrix, 4.0 zoom and 2 x 10⁵ present counts. There was no statistical difference between the thyroid masses evaluated by stereology on transverse, sagittal and coronal slices in the same condition. But in different acquisition zoom settings, the results were different. When the acquisition zoom was set at 2.0, the evaluated thyroid mass was most close to the thyroid model's real weight. Conclusions: The thyroid mass evaluated by thyroid static imaging composed with pixel will be influenced by the different acquisition parameters. The thyroid mass evaluated by thyroid tomography composed with stereology is related to the acquisition zoom setting. (authors)