An overview is given of th e concept and basic properties relevant to the laser wakefield accelerator, the plasma beatwave accelerator, wakefield accelerators driven by multiple laser pulses, and selfmodulated laser wakefield accelerator. Recent e xperimental results are also summarized. Generation mechanism of plasma wave is introduced, as well as the trapping and acceleration of electrons in the plasma wave. Some limits on laserplasma accelerators are discussed associated with th e future prospect of laserplasma accelerators.