Abstract: The invention relates to a video encoding and decoding technical field of the signal processing, especially relates to a method for video clip assisted by clip identifier. The method defines a clip identifier on the video encoding and decoding rule as an identifier used specially for video stream clip. If the encoded video bit stream is clipped, then said clip identifier is inserted to the bit stream or used to replace the original identifier which functions as a start flag. The clip of the video bit stream can be operated conveniently by the invention. The features of the invention are: the bits, which mark whether the clipped video bit stream may be decoded and displayed incorrectly or not, are not required to appear in the unclipped bit stream; if it clips at a certain point of the bit stream, then said identifier will appear at this point to indicate that a problem in which the picture can not be decoded normally due to the predictive reference data being clipped may appear.