An access system and method for transmitting Ethernet signals and mobile communication signals. The system includes a near-end host unit and remote-end user units. Through the near-end host unit, the Ethernet signals and mobile communication signals can be combined. The near-end and remote-end host units are connected through four pairs of twisted pairs. The combined Ethernet and mobile communication signals are sent to a user terminal for providing broadband access service and wireless access service. Premises network resources can be used without re-laying category 5 cables, so the investment is less and it is quick and convenient to provide service. Furthermore there needs to be added only one host unit beside the optical network unit equipment, and replace the user terminal simultaneously. Power is not needed to be taken at the user's home. The placement position of the terminal is flexible without being limited by the power-taking positions.