Objective: To investigate the changes and clinical significance of flow mediated dilatation (FMD) and serum endothelin-1 (ET-1), creatine phosphokinase (CK) level in patients with mania. Methods: 100 patients with mania who were treated in our hospital were selected as mania group, and 50 healthy volunteers at the same period were selected as control group. The FMD and serum ET-1, CK level before treatment of the subjects in 2 groups, and patients with different degrees of mania were compared. The BRMS score, FMD and serum ET-1, CK level of mania patients before and after treatment were also compared. The correlation between FMD, ET-1, CK and BRMS score before treatment were also analyzed. Results: Before treatment, the serum ET-1 and CK level of mania patients were obviously higher than those in control group, while the FMD was obviously lower (P˂0.01). Moreover, there were significant differences in serum ET-1, CK level and FMD among patients with mania of different degree (P˂0.01). After treatment, the BRMS score and serum ET-1, CK level were significantly lower than that before treatment, while the FMD was significantly lower higher (P˂0.05). Pearson correlation analysis showed that serum CK, ET-1 level were positively correlated with BRMS score of mania patients (P˂0.05); The FMD was negatively correlated with BRMS score of mania patients (P˂0.05). Conclusions: FMD and serum CK, ET-1 level can be used as important indicators for assessing the severity and changes of mania.