The present invention relates to the field of touch pad. In particular, there is provided a touch pad comprising a storage unit, a sensing electrode array unit and a processing unit. A trace graph composed of coordinate values of positions on the sensing electrode array unit, touched by a user in the course of operating the touch pad is recorded; comparison is made between the trace graph and a graphical password to generate a comparison value. Since the touch pad is provided with the function of recognizing the graphical password, a computer can use it to input graphical password, text password, and various characters in various states such as BIOS state and a variety of OS states, which can enhance the security of devices such as computers and make the product more interesting and easy to use.