Present invention provide a method, an apparatus, and a system for playing a video file. The method includes: receiving a video playback request sent by a video terminal, where the video playback request carries a video file identity and information about a video media capability of the video terminal; determining that a decoding resource for decoding a video file that corresponds to the video file identity already exists, and using the decoding resource to decode the video file in an internal format; if it is determined that a first encoding resource for obtaining, through encoding, a video file that complies with the video media capability of the video terminal exists, using the first encoding resource to encode the video file in the internal format into a video file that complies with the video media capability of the video terminal, and sending the encoded video file to the video terminal.