An apparatus and method for introducing micro-volume liquid. The method includes the following steps. A multi-channel inkjet print head is provided. The multi-channel inkjet print head includes a nozzle plate and a cartridge. The nozzle plate includes a plurality of nozzles. The cartridge includes a plurality of channels, communicating with the nozzles on the nozzle plate, and a plurality of openings located at the channels. The nozzle plate contacts with a buffer. The buffer is introduced into the channels via the nozzles on the nozzle plate by pressure. Reagents are introduced into the channels through the openings.