A method for adjusting the working frequency of a chip is provided. The method detects a frequency adjustment range of a graphic chip when a system is booted. Then, an application program in full screen mode is executed, and a control hot key is enabled. Afterwards, an input of the control hot key is received to display a user interface. Finally, an input frequency inputted from the user interface is received, and the working frequency of the graphic chip is adjusted according to the input frequency in the frequency adjustment range. Therefore, even though the application program is executed in full screen mode, the working frequency of the graphic chip can still be adjusted according to requirements in any time, which is convenient for the user.