In a compression data editing apparatus, a smooth switching (edition) having no noise is enabled to be performed. A code train 10 is supplied to an MPEG decoding circuit 2 and is delayed by a fixed time and, after that, it is decoded into an audio signal. In this instance, the operation is temporarily stopped for a block which is repeated. When an offset value extracted by an offset extracting circuit 3 lies within a predetermined range, the repeat pulse is detected and supplied to the circuit 2. A flag is set to a frame in which the pulse is detected. In the circuit 2, the decoding is temporarily stopped in the code block which corresponds to the pulse and was recorded at the second time. The decoding is restarted after the next block was inputted. In the circuit 2, the supplied code train 10 is supplied to, for example, a synthesis filter of 512 taps and is converted into the audio signal. Therefore, data of 256 samples near the boundary of the adjacent blocks is mutually influenced and a correct audio signal 14 is outputted.