α-Enolase is an important glycolytic enzyme located on the cell surface of various pathogenic streptococcus which is capable of plasminogen binding and is contribute to tissue invasion. In the present study, we cloned and purified the a-enolase of S. agalactiae from tilapia. The plasminogen-binding ability of α-enolase was confirmed by western-blot. The location of a-enolase was demonstrated by using the methods of cell wall associated protein extraction and flow cytometry. Moreover, the role that α-enolase played in the GBS adherence to EPC cell line was analyzed. These results suggested that a-enolase of S. agalactiae was capable for the S. agalactiae to invasion by plasminogen activation and the adherence ability of α-enolase highlight its crucial role it played in the pathogenesis of S. agalactiae.