Abstract: Physically modified atmosphere method was used to achieve safe environmental protection of tobacco storage. A technology with nitrogen generating equipment was used to produce high concentrated nitrogen, then pump the high concentrated nitrogen into sealed tobacco of different growing areas and different grades, so that the difference between physical and chemical atmosphere methods could be compared. The result showed that both kinds of nitrogen generating equipment could produce 99.5%-99.9% concentration of nitrogen. Physical modified atmosphere method could make the concentration of oxygen in sealed tobacco stack lower to 2.0% with shorten time (the shortest time was 8 days.). The de-oxygenation efficiency were related to inner membrane and package manner of tobacco. The physical modified atmosphere method could use in sealed tobacco storage.