Abstract: A tobacco leaf curing system comprising an air tight curing house divided by a porous floor plate into an upper curing barn and a lower blast chamber, the curing barn being provided at its upper portion with a circulation port and an outlet port; a circulation duct passageway containing duct fan means and heating means, said circulation duct passageway communicating with the circulation port for drawing air from the curing barn, said air being compressed by said duct fan means and heated by said heating means and then reintroduced into the blast chamber through a blast port; an automatic temperature regulator associated with the burner of the heating means for automatically igniting or extinguishing said burner according to variations appearing on a wet-bulb temperature sensor so as to regulate the temperature and humidity of the air to be sent to the blast chamber; an inlet control system comprising a cylindrical damper provided with openings and located in said circulation duct system, said inlet control sy