The global warming by increased CO2 will effect of plant pathogenic microorganisms and resistance of host plants, and it is expected to affect host-pathogen interactions. This study used Capsicum annuum L. and Xanthomonas euvesicatoria, a pathogenic bacteria of pepper, to investigate interactions between hosts and pathogens in a complex environment with increased cultivation temperature and drought stress. As a result, the bacterial spot disease of C. annuum L. caused by X. euvesicatoria was 35°C higher than 25°C. In addition, the effect on water potential on bacterial spot disease was much greater water potential -150 kPa than -30 kPa. The disease progress and severity higher than water potential -30 kPa. This result will useful for understanding interaction with red pepper and X. euvesicatoria under the complex environment with increased cultivation temperature and in water potential -150 kPa drought stress in the future.