Abstract:Parasitic root weed Orobanchespp. has already severely constrained the development of agriculture in many areas around the world and it is therefore urgent to develop effective control measures of Orobanchespp. As this parasitic root weed has a specific life cycle and is highly intimate to its host plants, it is difficult to develop an ideal control measure based on traditional practices. Up till now, there has been no measure to effectively control Orobanchespp. to make it completely harmless to host plants and easily applicable at large field scale. Among the control measures available, the use of micro-organisms has increased concerns. In this paper, national and global efforts to control Orobanchespp. by the use of micro-organisms and the mechanisms of the control measures are summarized. Until now, research on biocontrol of Orobanchespp. by the use of micro-organisms has focused on pathogens of Orobanchespp., such as Fusariumspp. and symbiotic bacteria (such as Rhizobiumspp.) of host plants. The mechanisms of the use of micro-organisms to control Orobanchespp. have involved in two ways:one is to secrete metabolites that directly inhibited the germination and growth of Orobanchespp. or to indirectly affect the germination of Orobanchespp. by the degradation of the chemical compounds which stimulated the germination of Orobanchespp.; another way is to indirectly affect the parasitic behavior and growth of Orobanchespp. by enhancing host plant resistance against Orobanchespp. Furthermore, the possibility and research advances by the use of soil-borne antagonistic micro-organisms against soil-borne plant pathogens in controlling weedy Orobanchespp. have been discussed. Both soil-borne plant pathogens and Orobanchespp. first infected plant roots underground and then damaged normal growth of the plants. Resistances of plants to soil-borne plant diseases were similar to those of Orobanchespp. Thus, micro-organisms that isolated from soils and controlled soil-borne plant diseases may also have the potential to control parasitic root weed Orobanchespp. We screened out one actinomycete strain ( Streptomyces enissocaesilisSveshnikova) and one actinomycete strain ( Streptomyces pactumBhuyan B.K.) from soil-borne mic-organisms that against soil-borne plant diseases. These two strains effectively controlled O. cumanaWallr. and O. aegyptiacaPers., respectively, in pot experiments. The application of S. pactum inoculum in field experiment reduced the epigaeous number of O. aegyptiacaand increased the yield of tomato, simultaneously. In conclusion, the use of micro-organisms to control parasitic root weed Orobanchespp. is an effective measure.