Abstract: A method of controlling a computer to execute relevant actions through reading bar codes includes the steps of using an optical identifying unit to scan at least one bar code and convert the read bar code into a digital signal, inputting the digital signal to an operating system of the computer via a peripheral interface, such as USB, PS2, RS232, etc., using related control software to map the received digital signal to a corresponding synopsis of functions to execute in the control software, locating index and data in the synopsis corresponding to the digital signal, and executing at least one control procedure corresponding to the located index and data to drive the computer to execute relevant actions. The method of controlling a computer through reading bar code may substitute for the conventional input peripherals and reduce previous complicate control procedures to only one simple movement of reading a bar code.