The present invention provides a biomedical monitoring system combining a mobile device. Signals can be transmitted between the sensing device and the mobile device via the audio interface by modulating and demodulating the audio signals or encoding and decoding the digital signals. Thereby, it can be applied extensively to mobile devices having audio jacks and thus bringing more convenience. In addition, because the mobile devices inherently have the functions of operational processes, transmission, storage, interface operations, result displaying, network connection, image extraction, and power supply, the required components in sensing devices can be simplified substantially and hence reducing the volume and the manufacturing cost.
