Abstract: We have extended the classical Mckendrick-Foerster age structured population model to study the effect of population area size on the transmission dynamics of tuberculosis in an age-structured population, in which infective recovers, after treatment and becomesusceptible again when in contact withthe disease. The natural mortality rate is assumed density and area size depended, with the population assumed to be in proportionate mixing. We defined a model in which the area sizes and the total population influences the rate at which death by nature occurs in the population. This model is extended to study the influence the area size of the population has on the natural mortality rate, life expectancy of the population and the transmission dynamics of the infection. The analytical solutions of the governing equations are obtained. The existence of the non trivial steady states is examined with their local and global stability.