The allergic constitution is a common biased constitution state.This paper discusses the understanding of allergic constitution from the basic principles of traditional Chinese medicine constitution,such as life process theory,endowment inheritance theory,physical-spirit composition theory,and environmental constraints theory.From the perspective of life process theory,at different ages,allergic constitution may change with the rise and fall of qi and blood in the body,and there is a general trend of qi and blood in the body from immature to strong and then to weak.From the perspective of endowment inheritance theory,the allergic constitution is closely related to heredity and has the tendency of family aggregation.From the perspective of physical-spirit composition theory,people with allergic constitution have physical characteristics such as nose,airway reaction,intestine,and skin reactions,and psychological characteristics such as introversion and the tendency to produce anxiety,depression,and tension.From the perspective of environmental constraints theory,the formation of allergic constitution is related to the differences of seasons and geographical environments.By discussing the characteristics of allergic constitution,we can deeply understand allergic constitution and provide reference for better grasping allergic constitution and improving the quality of life of allergic people.