As a major G-actin-sequestering protein,thymosin beta4(thymosin β4,Tβ4) is in almost mammalian cells.It has a number of physiologic functions,including the promotion of cell migration,stem cell differentiation,angiogenesis,inhibition of cell apoptosis and immune regulation,which plays an important role in the wound healing,tumor metastasis,inflammation control and so on.This review summarizes relative studies about Tβ4,including its properties in cell migration,transdiffe-rentiation and research progress in ophthalmology.