Objective To investigate the effects of ambient temperature on airflow and particle deposition patterns in human respiratory tract. Methods The gas-solid two-phase flows in human respiratory tract with mucus layer were simulated using computational fluid dynamics (CFD) method. Particles with 8 different sizes (1-8 μm) in human respiratory tract under six different ambient temperatures (-25,-15,0,15,26. 7,45 ℃) were considered.Results The difference between the flow velocity and the average flow velocity under six temperatures could reach 39. 42% . The difference between the air flow turbulent kinetic energy and the average turbulent kinetic energy under six temperatures could reach 11. 59% . The difference between the change of airflow temperature and the average change of air flow temperature under six temperatures could reach 82. 4% . The difference between the particle total deposition rate and the average value of the total deposition rate under six temperatures was 14. 72% . The difference between the particle local deposition rate and the average value of the local deposition rate under six temperatures could reach 37. 08% . Conclusions The ambient temperature will have an impact on the properties of the airflow field, and further affect the properties of particle deposition in human respiratory tract. Therefore, it is necessary to consider the influence of ambient temperature when accurately predicting patterns of particle transport and deposition in human respiratory tract is required.