A memory storage device includes a host interface to be connected to a terminal host, a controller connected to the host interface, and a fingerprint sensor and a memory module both connected to the controller. The controller communicates with the terminal host by handshakes and causes the terminal host to automatically run a suitable driver and a suitable application program from the memory module to the terminal host. The terminal host receives an instruction from a user through the driver and the program and informs the controller to control the fingerprint sensor to read to-be-recognized fingerprint data of the user. The terminal host utilizes the application program to process and judge whether or not the to-be-recognized fingerprint data substantially matches with template fingerprint data stored in the memory module, and further enables a specific block of the memory module to be accessed by the terminal host according to a matching result.