Sarcopenia is an age-associated, progressive and generalised skeletal muscle disorder. However, almost every study about sarcopenia is concerning on measurement of lean body mass or far-free mass rather than skeletal muscle mass. Bioelectrical impedance analysis (BIA), dual energy X-ray absorptiometry (DXA), computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound examination are all commonly used methods of skeletal muscle measurement for sarcopenia, but all of them are flawed. Most of them are indirect measurement of simple indexes for anatomical skeletal muscle mass, and a few are direct measurement of index as anatomical muscle mass. D₃-creatine dilution, however, is the most promising approach to directly measuring skeletal muscle mass. It provides a direct and accurate measurement of creatine pool size and skeletal muscle mass, and also can reflect skeletal muscle function. It is expected to be the most promising biochemical examination for sarcopenia, which can make up for the defects of the current common methods.