Sarcopenia is a geriatric syndrome characterized by reduced muscle mass combined with decreased muscle strength and/or decreased physical performance. In recent years, sarcopenia has become a hot topic in geriatric research, and new achievements have been made in the exploration of serum biomarkers for sarcopenia. In this article, we review the serum biomarkers associated with sarcopenia, and focus on muscle-specific biomarkers, oxidative stress-related biomarkers, nutrition-related biomarkers, endocrine-related biomarkers, neuromuscular junction (NMJ)-dysfunction-related biomarkers, and microRNA markers in addition to traditional inflammation-related biomarkers. The phenotype and pathogenic mechanisms of sarcopenia are complex, therefore, it is difficult to identify sarcopenia based on a single biomarker. Clinical prediction models based on integrating multiple biomarkers and other clinical features are the direction of future research.