The multiplex PCR was used to identify the Shiga toxin-producing Escherichia coli in meat, Raw beef samples inoculated with E. coli O157:H7 were stored in a cooler for 1 h, 6 h, 12 h, 24 h, 48 h, and 96 h at 2 degrees C and in a freezer for 1 h, 6 h, 12 h, 24 h, 48 h, 72 It, 96 h, 1 week, 2 weeks, 3 weeks, 4 weeks, and 2, 3, 4, 5 or 6 months at -18 degrees C, and after the storage period were tested with multiplex PCR assay. It was found that stx gene of E. coli O157:H7 could be properly identified by the use of the mPCR technique in beef samples stored up to 96 h at 2 degrees C or 6 months at -18 degrees C.