Bacteriorhodopsin(bR) in the purple membrane with the function of proton pumping is an integral membrane protein, and it is a prominent prototype of the family of seven α-helical proteins. At present, bR with light-driven proton pump is one of the best char1acterized active ion-translocating proteins. It is very possible that bR will be the first membrane protein whose vectorial transport mechanism is understood at the molecular and even atomic level. The progress on the structure, photocycle and proton pump of bR in recent years are briefly introduced.