An operating method for an integrated interface of a PDA and a wireless communication system includes the following steps. Firstly, when the wireless communication system starts to operate from a standby mode, a state signal is transmitted from the wireless communication system to the PDA. Then, if the PDA receives the state signal when the PDA is in a sleep state, the PDA is wakened and an input source of an audio element inside the PDA is switched to the wireless communication system. An electromagnetic wave signal is received by a wireless communication element and converted into audio data. Afterwards, the audio data is transmitted from the wireless communication system to the PDA and outputted by the audio element.