Sarcopenia is a syndrome associated with low muscle mass, muscle strength and physical performance. The morbidity rate of sarcopenia is pretty high in elderly people who are lake of physical activity, chronic disease patients and patients with malignancy. Patients have higher risks of falling, frailty and disability, and are more likely to be independence. Sarcopenia also impact on the quality of life and clinical outcome directly, and if we pay enough attention to sarcopenia early in life, it can help us delaying frailty. Sarcopenia are categorized as aged-related sarcopenia, sarcopenia with malnutrition, sarcopenia associated with activity, disease-related sarcopenia. Aging, endocrine changes, chronic inflammation, cachexia, malnutrition, vitamin D deficiency can lead to sarcopenia. The European Working Group on Sarcopenia in Older People revises their consensus recently, and  recommends using muscle strength as the most important parameter of sarcopenia, and they updates its algorithm for sarcopenia casefinding, diagnosis and severity determination. Mechanism of sarcopenia has been realized within more and more studies developping. Nutrition supplement, resistance exercise and hormone replacement therapy can improve muscle mass and strength, delay function decline, improve quality of life. Etiology of sarcopenia is not integral yet, pharmacotherapy still needs more powerful evidence.