Plague is a potentially fatal infection in humans caused by the bacterium Yersinia pestis, transmitted naturally from rodent reservoirs to humans via fleas. Human diseases may also result from contact with blood or tissues of infected animals or exposure to aerosolized droplets containing bacteria. Pneumonic plague is typically diagnosed in humans with with high mortality. It has a long history for plague as an agent of biowarfare, and poses a serious threat to international security. In human history, there were three outbreaks of plague all over the world, about 200 million people died from the disease. The increasing trend of plague epidemic in recent years, some regions and countries in the world still have the outbreak of the plague. It implies that safe and effective vaccine is urgently to developing. Althought the killed whole-cell plague vaccine and live attenuated vaccine have been licensed, these vaccines cause significant adverse reactions, including fever, headache, malaise, lymphadenopathy, erythema and induration at the injection site with high degree of immune variability. They are rarely used today because of toxicities, limited evidence for efficacy to prevent plague, and limited commercial availability. Based on the researches in the last twenty years,the recombinant subunit vaccines comprised by fraction 1 capsule(F1)and virulence-associated (V)antigens as the main composition have caused widely attention with providing greater protection than vaccines comprised of either subunit alone. This study was aim to exploring the safety and immunogenicity of a new type plague subunit vaccine which comprised by native F1 antigen and recombined V antigen (F1+rV).