Provided is a real-time streaming protocol (RTSP) based progressive streaming method. The progressive streaming method based on a real-time streaming protocol, wherein a server transfers SDP information and performs streaming of a contents file to a client connected, the method including the steps of: a) if a “pause” request message is received from the client, transmitting a “pause” response message including the number of TCP packets already transferred to the client, and pausing streaming of the contents file; and b) if a “replay” request message including the number of the TCP packet to be transferred is received from the client, transmitting a “replay” response message and restarting transmission of the TCP packets from the next TCP packet to the TCP packet transferred to the client before the contents file is paused.