Ropporin has been identified as a spermatogenic cell-specific protein and may be involved in sperm maturation, motility, capacitation, hyperactivation and acrosome reaction. However, latest studies have shown that Ropporin is expressed weakly in normal non-testis tissues and highly in hematologic malignancies. Its highly conservative expression in mammalians demonstrates its importance to life. This paper updates the characterization, expression and its distribution, and biological function of Ropporin, and the advances in the clinical researches of the protein.