Abstract: Autoimmune encephalitis (AE) is an inflammatory disease in central nervous system (CNS), which is related with neuronal autoantibodies or CNS autoimmune biomarkers. Neurofilament light chain (NfL) is selectively expressed and the most important protein in neuronal cytoskeleton. The elevated NfL has been confirmed as a biomarker for the development or progression of various neurodegenerative diseases. Recent studies have shown that NfL is associated with early      screening/diagnosis, disease progression/therapy and prognostic checking/assessment of AE, which is expected to be a potential biomarker for AE therapy. Therefore, NfL is systematically reviewed from basic structure and function and detection methods to AE diagnosis, especially emphasizing on early screening diagnosis, disease progress monitoring and prognosis treatment evaluation.