BACKGROUND:　Recently,　health　care　and　disease　prevention　are　more　and　more　important　in　people＇s　daily　life.　Human　body　communication　(HBC)　is　an　emerging　short　distance　wireless　communication　mode,　which　is　quite　suitable　for　the　communication　between　the　wearable　human　health　care　equipment.　However,　most　research　on　HBC　mainly　focuses　on　the　electromagnetic　model　and　the　circuit　model　of　equivalent　human　and　the　in　vivo　experiment　is　based　on　the　commercial　equipment.　OBJECTIVE:　The　aim　of　this　paper　is　to　design　a　circuit　device　for　measuring　the　attenuation　of　the　human　body　channel　based　on　a　floating-ground-electrode　method.　METHODS:　This　paper　proposed　a　new　floating-ground-electrode　method　so　as　to　solve　problems　of　power　and　high　frequencies　interference　and　impedance　matching.　A　circuit　module,　including　signal　generator,　analog　frontend　circuit　and　MCU,　was　designed　to　initially　replace　the　spectrum　analyzer　to　measure　the　attenuation　of　the　human　body　channel.　The　floating-ground-electrode　added　to　the　receiving　end　of　the　human　body　channel　was　connected　to　the　ground　of　the　analog　frontend　circuit,　forming　an　equal　potential　circuit.　The　three-electrodes　of　the　receiving　terminal　can　act　as　a　differential　probe,　since　one　electrode　is　connected　to　the　ground　and　the　other　two　electrodes　achieved　signal　input　and　output　respectively.　RESULTS:　The　results　showed　that　the　experimental　data　of　channel　attenuation　were　similar　to　the　measured　value　of　the　spectrum　analyzer.　The　maximum　absolute　error　was　1.148　dB　and　the　relative　error　was　3.55%.　In　addition,　different　sizes　of　the　floating-ground-electrode　cannot　affect　the　attenuation　path　of　human　body　channels.　Moreover,　the　common　mode　rejection　ratio　(CMRR)　was　approximated　to　the　value　of　the　commercial　differential　probe.　CONCLUSION:　This　paper　proposed　a　new　floating-ground-electrode　method　for　measuring　the　attenuation　of　the　human　body　channel.　It　could　provide　the　possibility　for　the　dynamic　measurement　of　attenuation　and　take　the　place　of　the　spectrum　analyzer　and　make　the　process　of　experiments　simple　and　efficient.