Abstract: A simple, high-efficiency electrochemiluminescence (ECL) sandwich-type immunosensor was constructed for the sensitive detection of Myoglobin (Myo) based on the resonance energy transfer (RET) effect between cadmium sulfide nanowires (CdS NWs) and gold nanoparticles (Au NPs). Due to the perfect overlap between the ECL emission spectrum of CdS NWs and the UV-visible absorption spectrum of Au NPs, RET could occur between CdS NWs and Au NPs, resulting in the decrease of ECL signal from CdS NWs and thus achieving the sensitive detection of Myo. Under the optimized conditions, the linear range of Myo was from 1.0×10^-12 to 1.0×10^-7 g/mL and the limit of detection was 8.8×10^-13 g/mL. This sensor has been used for the determined of Myo in human serum samples. The results were agreement with the values provided by the hospital and the relative errors was no more than 7.5%, suggesting the potential practical application capability of the method.