The present invention relates to a method and apparatus for providing a calling number of an incomplete call, and in more detail, a method and apparatus for providing a calling number of an incomplete call for a receiving terminal when the incomplete call, which cannot receive a call, occurs. A calling number providing system provides the calling number of an incomplete call, wherein the system comprises a TCAP connector, a TCAP message receiver, a TCAP message analyzing unit, an incomplete call logging unit, a message informing unit, a controller, a message searching unit, a short message creator, a database broker, and SMCI/SMPP message constructing unit, a short message dispatching unit, and an SMCI/SMPP connector.