The rhizosphere is the dynamic interface between plant and soil.Through this interface,plants release photo-assimilated substances,which stimulate soil microbial activity.Microorganisms in turn transform the organic nutrients to inorganic forms,facilitating the uptakes by plants.This above-and below-ground feedback interaction constitutes the base for ecological functioning of the terrestrial ecosystems.Great advances have been achieved since the German scientist Lorenz Hiltner defined the term ‘rhizosphere’ 100 years ago.Particularly,the recent development of molecular ecological tools has largely expanded the knowledge of microbial diversity in the rhizosphere.To exchange the proceedings and document the perspectives and challenges in rhizosphere researches,the International Rhizosphere Congress was held September 2004,in Munich,Germany.Here we review the recent advances in:(1) the developments of research methods for rhizosphere microbiology;(2) the biodiversity and function of the rhizosphere microorganisms;(3) the GMOs' environmental safety;and (4) the rhizosphere bioremediation.