Objective: To compare the specific IgE positive rates of the patients between allergic respiratory diseases and respiratory infectious diseases in Guangzhou, the relationship between the co-sensitization of house dust mite (HDM) allergen and Aspergillus fumigatus (AF) allergen and asthma, allergic rhinitis with asthma, pneumonia, upper respiratory infections, bronchitis, serum total immunoglobulin E (total Immunoglobulin E, tIgE) and age were analyzed, to provide the basis for the prevention and treatment of respiratory allergic diseases and respiratory infectious diseases in this area. Methods: A total of 2 535 patients with confirmed respiratory allergic diseases and respiratory infectious diseases were selected retrospectively from the outpatient or inpatient department of the First Affiliated Hospital of Guangzhou Medical University from April 2017 to June 2021 and detected HDM and AF specific IgE (sIgE) by the ImmunoCAP system. The age range was 1 to 89 years. The median age was 5 years. The average age was 9. ≤3 years old group n=894, 4-6 years old group n=721, 7-18 years old group n=615, 19-49 years old group n=207, >49 years old group n=98. There were 1 596 males (62.96%) and 939 females (37.04%). There were 1 279 cases of allergic diseases and 1 256 cases of respiratory infectious diseases. The different disease groups were divided into asthma group (411 cases), allergic rhinitis group (458 cases), allergic rhinitis combined with asthma group (410 cases), pneumonia group (463 cases), upper respiratory tract infection group (299 cases) and bronchitis group (494 cases). The difference of specific IgE (sIgE) and tIgE between HDM and AF was analyzed. For statistical analysis, continuous variables were tested by Mann-Whitney U. Classification data by chi-square test or Fisher's exact test. Results: 1 313 (51.79%) patients were sIgE positive for HDM allergen, 65 (2.56%) were sIgE positive for AF allergen, and 50 (1.97%) were both positive. In the respiratory allergic disease group, 877 cases (68.57%,877/1 279) were positive for HDM allergen sIgE, 57 cases (4.46%,57/1 279) were positive for AF allergen sIgE, and 44 cases (3.44%,44/1 279) were both positive; 436 cases (34.71%,436/1 256) of respiratory infectious diseases were positive for HDM allergen sIgE, 8 cases (0.64%,8/1 256) were positive for AF allergen sIgE, and 6 cases (0.48%,6/1 256) were both positive. In monosensitization, the HDM allergen sIgE sensitization rate was the highest in the allergic rhinitis & asthma group, at 80.24% (329/410). The positive rate of HDM allergen sIgE in male patients was 53.76%(858/1 596), and the positive rate in female patients was 46.22%(434/939), and the difference between the two was statistically significant (χ2=13.449, P<0.001). In polysensitization, asthma patients (5.35%,22/411) had the highest positive rate of HDM sensitization with AF, followed by allergic rhinitis patients (3.06%,14/458), allergic rhinitis with asthma (1.95%,8/410). The positive rate of respiratory infectious diseases such as pneumonia (0.43%,2/463), upper respiratory infections (0.33%,1/299), and bronchitis (0.61%,3/494) with AF was extremely low. The positive rate of HDM combined with AF in infants(≤3 years old group,0.34%, 3/894; 4-6 years old group, 0.97%, 7/721)was significantly lower than that in teenagers and adults(7-18 years old group,3.58%, 22/615; 19-49 years old group,6.28%, 13/207;>49 years old group,5.10%, 5/98).In the patients with HDM and AF combined sensitization, HDM sIgE levels were distributed in all grades, and AF sIgE levels were mainly in grades 1, 2, and 3. Conclusion: The positive rate of HDM combined with AF was higher in patients with respiratory allergic diseases such as asthma, allergic rhinitis, and allergic rhinitis combined with asthma, suggesting that clinical attention should be paid to the combination of HDM and AF in patients with asthma and allergic rhinitis, especially adults, more likely to be combined with AF.