The widely distributed root knot nematodes infect various kinds of plants,and are one of important pathogens.Biological control of root knot nematodes may be one desirable approach to nematode management in practice.The paper reviews the current status and achievements in the studies of biological control of root knot nematodes.Some examples of fungi and bacteria to control root knot nematodes are given.Biological control of root knot nematodes is conducted by enhancing the activity of naturally occurring antagonists or by introducing other antagonists.A lack of urgent information on some aspects such as risk analysis of biological control,nature of suppressive soil,pathogenic diversity and epidemiology is put forward.Possible new approaches and future directions are discussed.