Security method of a portable device

A security method of a portable device, the security method comprising:

• an application program of the portable device receiving a command of an owner when the portable device is powered on;
• the application program notifying a basic input/output system to set a protection variable in a read-only memory, and notifying the owner to set a password in a setup menu of the basic input/output system after the application program receives the command of the owner;
• a keyboard controller turning off the portable device to enable the protection variable after the basic input/output system sets the protection variable in the read-only memory and the setup menu of the basic input/output system stores the password;
• and
• the basic input/output system checking a password inputted to the portable device at least once and the basic input/output system executing a corresponding operation according to a check result whenever the portable device is powered on after the protection variable is enabled.