Legume-Rhizobial Symbiosis (LRS ), Arbuscular Mycorrhiza (AM ) and associations with Plant Growth-Promoting Bacteria (PGPB) implement nutritional and defensive functions in plant, improve soil fertility, and thus are appropriate to be used for sustainable crop production and soil restoration. Based on synergism and evolutional commonality of the symbioses, we propose a multi-component plant-microbe system with legume plant as a main component. Advances obtained from simultaneous inoculation of legumes with various beneficial microbes are summarized. Basic principles of legume breeding to improve effectiveness of interaction with a complex of the microbes along with problems and prospects for development of multi-microbial inoculants for legumes (and nonlegumes) are stated.