The present invention relates to a micro-volume liquid ejection system, including an air pressure module, a micro-ejection unit which is connected with the air pressure module by a conduit, and a control circuit which is connected with the air pressure module and the micro-ejection unit respectively. The air is used as the pressure medium, resulting in improved cleaning process and reduced sample waste. The present invention includes an electric control circuit to pick up sample, eject sample and clean the conduits automatically, and enables handling of a multiplicity of samples. The present invention can be used for transferring or dispensing micro volume liquid including biological liquid on a nL and μL scale.