Abstract: This paper presents a systematic qualitative analysis of a class of agedependent epidemic model.By means of the theory of linear operator and C0semigroup in functional analysis,we first obtain the spectrum character of the corresponding epidemic operator,and then we study the existence and uniqueness of nonnegative solution of this model and the stability of this system.Finally,we reveal the quantitative relations between the control parameters and the total population number in each state via discussing...