Keloids, secondary to trauma, is a kind of skin disease with excessive connective tissue hyperplasia. It often happens in susceptible population. Spontaneous regression is considered to be extremely unlikely and it is easy to relapse after surgical resection. It is currently a challenging clinical problem of plastic surgery. The pathogenesis of KD is complex. It is the result of joint action of many factors, such as cytokine, cell signal transduction pathway, collagen metabolism, gene expression, cell proliferation and apoptosis, etc. In this paper, the cell signal transduction pathways and specific proteins related to KD were reviewed.