The present invention discloses a RFID access apparatus and a Transaction method using the same. The RFID access apparatus, coupled to a SD card socket disposed in an electrical terminal device including a controller unit coupled to said SD card socket and a radio frequency transceiver coupled to said controller unit, and being capable of accessing data recorded in a RFID tag through operating said electrical terminal device, comprising: a SD interface, coupled to said SD card socket for signal and data communication; a radio frequency access unit, coupled to said SD interface for reading data recorded in said RFID tag and writing data into said RFID tag; and a memory unit, coupled to said SD interface for storing data. By using the RFID access apparatus, a transaction method can be performed in the following steps: providing an electrical terminal device comprising a SD card socket; inserting a RFID access apparatus, comprising a memory unit recording an electric currency, into said SD card socket; accessing a price, stored in a RFID tag attached on a product, by operating said electrical terminal device; and making transaction.