The present invention provides a media negotiation method, device, and system for a multi-stream conference. The method includes: sending a media advertisement message that carries information about at least two media data objects; receiving a media selection message that carries information, about a media data object, selected by a second media entity; and determining a corresponding media data object according to the information, about the media data object, selected by the second media entity, and establishing a media transmission channel with the second media entity, so as to transmit the corresponding media data object to the second media entity through the media transmission channel. In embodiments of the present invention, more media data streams can be represented, and the representation accuracy and the amount of information of the media data stream can be improved