Objectives: The purpose of this study is to reveal the effect of Erhaungfang on relapsing multiple sclerosis (MS) and investigate the underlying mechanism. Methods: In our 2-year, randomized study, a total of 67 patients (diagnosed as MS) with age from 15 to 60 years were enrolled in this study. All patients in the acute phase were treated with methylprednisolone pulse therapy and then were randomly divided into treatment group (n = 50) administrated with erhuangfang, and control group (n = 43) without nothing. Magnetic resonance spectroscopy (MRS) was used to detect N-acetylaspartate (NAA)/creatine (CR) levels. At the end of a 2-year follow-up period, relapse rate, annual relapse rate, expanded disability status scale (EDSS) scores, and NAA/CR levels were compared between groups. Results: Relapse rate and annual relapse rate in the treatment group were significantly reduced after erhuangfang treatment (P < 0.05). There was no significant difference in terms of EDSS score between treatment group and control group and between after treatment and before treatment (P > 0.05). N-acetylaspartate/CR level was significantly correlated with the disease course (P < 0.05). There was no significant difference for NAA/CR levels in the treatment group before and after treatment (P > 0.05). Conclusions: Erhuangfang significantly reduced relapse rate and prevented progression of MS, which is an effective therapy for relapsing MS.