To provide a method for raising plants that have great vitality and that are strongly resistant to pests and can successfully compete against weeds. The invention provides a method for raising plants with enhanced immunity and biological activity to external and internal stresses. The present invention is characterized by the following: the method includes a step of applying to the target plants a plant immunopotentiating composition containing an immunostimulatory substance produced by the cytolysis that accompanies spore formation in aerobic endospore-forming bacteria; the immunostimulatory substance is obtained by culturing the aerobic endospore-forming bacteria, causing the bacteria to form endospores by placing the resulting culture liquid in starvation conditions, and then removing impurities including the bacterial cells that are formed into endospores from the culture liquid; and the aerobic endospore-forming bacteria belong to the MRE symbiotic bacteria group.