Brain computer interface(BCI) is an EEG based communication and control system between human and computer or other electric devices, which does not depend on the brain's normal output channels of peripheral nerves and muscles. It is a novel kind of human interface, may have applications in rehabilitation, control and other fields. The developming speed of brain computer research in recent years is high. Methods of how to use P300, SSVEP, ERS/ERD, SCP, spontaneous EEG and implanted electrode to realize BCI are introduced. Characteristic and limitation of different methods are discussed. Status, problems and application prospects of BCI technology are also included.