The present invention relates to a polypeptide specifically bound to phosphatidylserine and use thereof, and more particularly to a polypeptide having an amino acid sequence designated as sequence number 1 and specifically bound to phosphatidylserine, a phosphatidylserine detecting composition containing the polypeptide as an active ingredient, a detecting method of phosphatidylserine by using polypeptide, a apoptotic cell detecting containing the polypeptide as an active ingredient, a drug delivery composition containing the polypeptide as an active ingredient, a composition for treatment and prevention of a tumorous disease, and a composition for visualization of a tumorous region. A polypeptide having an amino acid sequence designated sequence number 1 is specifically bound to phosphatidylserine. Therefore, the polypeptide of the present invention is useful for detecting phosphatidylserine, furthermore detecting apoptotic cells expressing phosphatidylserine on the surface of the cell and tumor cells, and also useful for visualization of apoptotic cells or tumor cells.
