Abstract: OBJECTIVE To explore the effect of upper respiratory tract infection on olfactory dysfunction, so as to provide theoretical basis for clinical. METHODS A total of 515 cases of patients with advanced laryngeal carcinoma and laryngeal carcinoma from Jan. 2010 to Jun. 2015 were selected as research group, another 100 cases of healthy persons were selected as control group. The odor threshold value, olfactory bulb volume, and olfactory groove depth of the two groups were detected. RESULTS Totally 31 cases of patients had upper respiratory tract infection in research group, with the infection rate of 6.02%, their odor threshold value was (2.87±0.33), and the odor threshold value of uninfected patients was (0.89±0.21) (P<0.05) . The volume of olfactory bulb in control group was higher than that in research group, and the volume of olfactory bulb of uninfected patients was higher than that of infected patients in research group (P<0.05). The olfactory groove depth of the two groups had no difference. CONCLUSION Upper respiratory tract infection can reduce the size of olfactory bulb, increase the odor threshold value and reduce the olfactory function in patients.