Abstract:Sarcopenia is a geriatric syndrome characterized by decline in skeletal muscle mass， strength， and function. Its pathophysiological mechanisms involve multiple factors， ranging from muscle - specific processes（such as myokine secretion）to systemic changes（such as inflammation and amino acid metabolism disorders）. Currently，the diagnosis of sarcopenia primarily relies on clinical manifestations，functional assessments， and imaging examinations. In recent years， the discovery of biomarkers has provided important directions for early diagnosis，research into pathological mechanisms，and the development of intervention targets for sarcopenia. This review systematically explores imaging，functional biomarkers，and serological biomarkers of sarcopenia，aiming to provide a scientific basis for its diagnosis，prognosis assessment，and treatment decision-making.