Oligotrophic bacteria are a group of microbes living in oligotrophic environments. Their diversity and biomass are dominant in biosphere, and thus, play an important role in biogeochemical cycles. Since 1980s, their oligotrophic mechanisms, responses to starvation, and roles in ecosystems have been one of the most advanced subjects in microbial ecological research. Much attention has been paid to the theoretical values and applied perspectives of oligotrophic bacteria. This paper reviewed the concepts, nutritional types, physiological and ecological characteristics, possible oligotrophic mechanisms, and main research methods of oligotrophic bacteria, and their applications in bacteria examination of iatrology and in environmental monitoring for heavy metals. The applied perspectives of oligotrophic bacteria in environmental science were also discussed.