A two-stage mechanical tracheobronchial model (MTBM) of human lung’s tracheobronchial airways was designed, developed, and validated with the respiratory deposition data predicted by the International Commission on Radiological Protection. The MTBM assembly was based on widely used human lung’s morphological dimensions specified in the Ewald R. Weibel’s dichotomous lung morphometry. It could physically simulate the surface area and the Reynolds number of the trachea, main, lobar and segmental bronchi of the human lung. The experimental data agreed with the reported aerosol particle deposition measurements using the United State Pharmacopeia approved Andersen Cascade Impactor, which is often used for inhaled aerosol deposition studies.