Abstract: Objective: To determine the characteristics of ingested allergens and inhaled allergens in infancy and the relationship between them.Methods: 370 infants with allergic diseases were included in this study.Serum-specific IgE to milk,egg and pyroglyphidae were measured in all the patients with UniCAP System;the allergic rate of the three kinds of allergens in different ages,the cross allergy phenomenon between ingested allergens and inhaled allergens were all analyzed.Results: The prevalence of milk allergy and egg allergy went down with the age increasing,and the prevalence decreased obviously after the age of 3;The prevalence of pyroglyphidae allergy went down with the age increasing,and the prevalence increased obviously after the age of 2.There was no cross allergic phenomenon between the milk and pyroglyphidae except the >2-3 age group.Conclusions: Allergic phenomena in infancy and early childhood are mainly caused by ingested allergens,and will gradually develop tolerance with the age increasing and turn to inhalant allergens.So when ingested allergy symptoms are relieved,attention still should be paid to inhaled allergen-induced allergic phenomena.