Abstract: Objective To investigate the distribution of serum allergens in children with respiratory allergic or infectious diseases ,andthen provide evidence for the prevention and treatment of children 's respiratory allergic and infectious diseases.Methods The clinicaldata of 2 334 children aged 1 to l4 years old ( median 5 years)visited Shenging Hospital Affiliated to China Medical University fromApil 2019 to June 2022 were relospectively analyzed.All the children were diagnosed with respiratory allergic or infectious diseases.The Phadia 250 automatic fluorescence enzyme immunoassay system and its supporting detection reagents were used to detect serumslaE to allergens and statistical analysis was conducted using the GraphPad Prism 8.0 software.ResultsThe positive rates of sIgE toallergens in children with respirator allergic diseases ( n=1 151) and respiratory infectious diseases (n= 1 183) were 75.85% and47.68% , respectively. The main allergen in the children with asthma was a mixture of dust mites ( 44.18% ) , followed by a mixture offungi ( 40.64% ).'The main allergens in the children with allergic thinitis were a mixture of dust mites and weed pollen， both accountingfor 52.51% . The common allergen of respiratory infectious diseases was mold mixture (27.81% ) , followed by a mixture of dust mites(24.77% ) . The main allergen in children under 7 years old was a mixture of fungi (33.31% ) . As age increased , the positive rates ofallergens in different combinations increased. The positive rates of serum slgE. to dust mite mixture，dander mixture , and weed pollenmixture in children aged ≥ 7 years old were significantly higher than those in children aged ≤ 3 years old and 4-6 years old (P<0.000 1). The positive rate of serum slgE to allergens in male patients (64.33% ) was significantly higher than that in female patien's(56.3% ,x'=14.29, P=0.000 2) . Among various disease groups，the levels of slgE to dust mite mixture and weed pollen mixturewere distributed at levels 1-6，with the highest distribution rate at level 6 in allergic rhinitis.Each disease group was associated withone allergen or a combination of two allergens.As the number of allergen combinations increased,the positive rate of slgE gradually decreased. The tIgE levels in children with allergic rhimitis were significantly higher than those in children with asthma , upper respiratorytract infection, and lower respiratory tract infection (all P<0.005 ). Conclusion Dust mite mixture and mold mixture are common al-lergens in children with asthma ， while weed pollen mixture and dust mite mixture are common allergens in children with alleric rhini-tis. As age increases，children become more and more allergic to dust mite，mold , dander，weeds，and pollen.