[Objective] The paper was to understand the suitable meteorological indexes and key meteorological factors for infection and prevalence of tobacco brown spot. [Method] Tobacco brown spot disease in five topical mountainous climatic areas of Guizhou Province was investigated, and the difference of biological characteristics of different strains was analyzed indoor. Different meteorological conditions (light, temperature and humidity) were simulated in artificial climate box by using the uniform design method , and the difference of infection ability of Alternaria alternate in different climate zones was analyzed in leaves in vitro by hanging drop method. [Result] The infection rate of A. alternate in different climate zones of Guizhou Province showed certain difference. In low temperature and middle humidity (the humidity is 50%-60%, the temperature is 10-20 ℃) conditions, the pathogen could infect tobacco leaves, various strains had certain difference, but the difference was small. [Conclusion] The paper provided theoretical basis for prevalence prediction and control of tobacco brown spot. [Objective] The paper was to understand the appropriate meteorological indexes and key meteorological factors for infection and prevalence of tobacco brown spot. [Method] Tobacco brown spot disease in five topical mountainous climatic areas of Guizhou Province was investigated, and the difference of biological characteristics different meteorological conditions (light, temperature and humidity) were simulated in artificial climate box by using the uniform design method, and the difference of infection ability of Alternaria alternate in different climate zones was analyzed in leaves in vitro by hanging drop method. [Result] The infection rate of A. alternate in different climate zones of Guizhou Province showed certain difference. In low temperature and middle humidity (the humidity is 50% -60%, the temperature is 10-20 ° C) conditions , the pathogen could infect tobacco leaves, various had had certain difference, but the difference was small. [ Conclusion] The paper provided theoretical basis for prevalence prediction and control of tobacco brown spot.