The present invention provides an electronic device providing with a security mode and an operation mode, wherein the electronic device includes a touch panel having a sensing array. A sample fingerprint is fetched by using the sensing array; a detected fingerprint is fetched by sensing a fingerprint using the sensing array in the security mode. The sample fingerprint is compared with the detected fingerprint in the security mode, followed by unlocking the electronic device if the detected fingerprint matches with the sample fingerprint, and switch the electronic device into the operation mode. A control signal is generated in responsive to a touching event, followed by controlling a virtual object displayed on a display in responsive to the control signal.