Abstract: Objective:In order to provide anatomical data for diagnosis and therapy of diseases of nasal septum, the changes of thickness of nasal septum were studied. Methods: The width and length of nasal septum and nearby structures were observed and measured with 18 head specimens of coronal and horizontal sections. Results: The thickness of nasal septum is various at different area. The thickness of anterior one third of nasal septum is 10.8±1.2mm that it is the thickest of all parts. The posterior part is thinner with 1.5±0.3mm. The part of thickness consists of mucosa mainly and the thickness of mucosa is 8.6±0.7mm. Conclusions: This study has clinical significance such as nasal septum surgery, the hemorrhage of nasal cavity and nasal airflow obstruction.