Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system that leads to neurological disability. The diagnosis of MS relies on the MRI criteria, which can demonstrate dissemination in space and time. Exclusion of other demyelinating mimics is essential because there are no specific biomarker for MS and MRI criteria are still have imperfect. There is incremental improvements in MS treatment option that have contributed to the delay of disease progression. The early initiation of DMT may ameliorate the neurological disability. In this review, we discusses the new diagnostic MS criteria and summarize the evidences supporting the early treatment in the course of MS.