Abstract: Provided are a method for generating an instantaneous decoding refresh (IDR) unit for trick play, and a trick play system and method using the same. The trick play system includes: a speed information input unit configured to receive a speed value; a transmission condition determining unit configured to determine instantaneous decoding refresh (IDR) transmission conditions based on the speed value inputted through the speed information input unit; a double-speed IDR-unit generating unit configured to generate a double-speed IDR-unit by adjusting the number and data size of video frames to be transmitted in accordance with the transmission conditions determined by the transmission condition determining unit; and a transmitting unit configured to transmit the generated double-speed IDR-unit to an external user terminal.