An intra-frame prediction method and a prediction apparatus using the same are provided. The prediction apparatus includes an input data unit, a control unit, an selection unit, a processing unit, and an output data selecting unit. The input data unit provides surroundings pixels of a predicted block. The control unit provides an input selection signal, a computing parameter, and an output selection signal. The selection unit selects the surroundings pixels according to the input selection signal. The processing unit computes the selected surroundings pixels for producing a plurality of results according to the computing signal. The output data unit selects results according to the output selection signal.