An EDC generating circuit includes a memory unit, an EDC generating circuit, a header generator and an EDC correcting circuit. The EDC generating circuit, which is coupled to the memory unit, is used for generating a first EDC according to at least one main data, and for storing the first EDC to the memory unit. The header generator, which is coupled to the memory unit, is used for generating a header according to header information. The EDC correcting circuit, which is coupled to the memory unit, is used for reading the first EDC from the memory unit and for correcting the first EDC according to the header to generate a second EDC.