Abstract: A mobile communication device and a data verification system applying a smart card having double chips are applicable to data verification processing when the mobile communication device drives the smart chip to perform transaction with a front end access device. The mobile communication device includes a wireless communication unit, a processing unit and a smart chip. When the processing unit receives a transaction request sent by the front end access device or the processing unit executes a transaction procedure, the processing unit performs data verification processing during transaction through the smart chip.