We explore the structure and evolution of intermediate-mass stars. Under this, we focusrnon the mass-luminosity relation of the single main sequence interme diate-mass stars.rnWe derivate the stellar structure equations and put the fundamental stellar quantities inrnterms of mass. After this, we derivate the lifetime of intermediate-mass stars in threernnuclear burning phases and relate the stellar quantities with their lifetime. Thus wernpredict the relation MLR, MRR, and MTR in hydrogen core burning, hydrogen shell burning,rnand helium core burning. The mass-luminosity relation is in good agreement for O.Yu.rnMalkove observational work of the absolute MLR relation.In the effects of temperaturerngravity and nuclear reaction, the starâ€™s structure was varied. To determine the finalrndifferential results of starâ€™s structure equations, we must used the derivative of interiorrnstars structure equations with central radius r. This allows us to compute the M, T, P,rnL, and R relations. Those are quantities derived from the stellar structure equations.rnFrom those equations, we have obtained the mass-luminosity relation equation and usingrnnuclear reactions we studied the starâ€™s mass and age relation using the simplified formrnof the equations. We showed the graphical relationship of Mass to Luminosity, Mass tornTemperature, and Mass to Radius of stars in terms of a parameter of a nuclear burningrnlifetime.rnThe lifetime equation of the star in hydrogen core burning and the mass-luminosity equationrnare good ways to measure the mass-luminosity relation of B-type stars.