Bioleaching technology is an effective measure to deal with low-grade ore. However, Reserch in China mainly focuses on howt autotrophie microorganisms leach sulphide ore, while little research is carried out on leaching of oxidized ores by heter- otrophic microorganisms. Heterotrophic microorganisms have the potential in producing metabolites that are able to extract or dissolve nickel- and cobalt- contained low-grade nickel-cobalt oxidized ore via acidolysis, reduction, basification and complex- ation, which help to resolve the problems of nickel and cobalt resources shortage and offer technique supports to heavy metal pollution treatment. In the case of low-grade nickel-cobalt oxidized ore, weathered crust and secondary resources (metallurgical slag, waste batteries, spent catalysts, etc. ), this paper introduces the status of world's nickel and cobalt resources and types of low-grade nickel-cobalt oxide ore. Meanwhile, the current status of research on heterotrophic microorganisms leaching low- grade nickel-cobah oxidized ore is reviewed. The leaching conditions and difficulties of heterotrophic microorganisms leaching are pointed out. Finally, the development direction of future research on bioleaching of nickel-cobalt oxidized ore is proposed.