An apparatus for testing a driving circuit for a display is disclosed. The apparatus includes a selecting circuit, a reference voltage generator and an analog-to-digital converter (ADC). The selecting circuit includes many input terminals and an output terminal. The input terminals are respectively coupled to many output pins of the driving circuit, while the selecting circuit is used for selecting one of the output pins to electrically connect the output terminal of the selecting circuit. The reference voltage generator is coupled to at least one of the output pins for generating a reference voltage. The ADC is coupled to the output terminal of the selecting circuit for outputting a digital value based on a difference between an output voltage outputted from the output terminal of the selecting circuit and the reference voltage produced by the reference voltage generator.