Myasthenia Gravis（MG）is a neuromuscular autoimmune disease. Patients will have symptoms like ptosis, diplopia, dysarthria, dysphagia, generalized muscle weakness, and, in the most severe situation, respiratory insufficiently, even leading to life-threatening. As medical technology developing, there has been great progress in the diagnosis and treatment of myasthenia gravis. Due to longer life expectancy and aging population, there is a clear trend towards an increase in the prevalence of the disease. According to the number of valid catastrophic illness cards issued by Taiwan’s National Health Insurance, the prevalence of myasthenia gravis in Taiwan is estimated to be 187 cases per million people. Due to the nature of the disease, patients are affected in self-care ability, social, work, pursuing education opportunities and psychological aspect, thereby affecting their quality of life. In this study, using patient-reported outcome, obtained the quality-of-life through asking patients to fill out a self-administered questionnaire directly. The results will be provided to the clinicians to deliver better patient-centered service. This study was a cross-sectional research. Patients were recruited from the outpatient neurology clinic of a single hospital, individuals as ananlysis unit. Data were obtained from two parts. Health-related quality-of-life and socio-demographic features were collected from the structured questionnaires, and clinical data were acquired from the database registered in the sample hospital. The study was conducted between 1st July 2010 and 31st August 2014. There were 132 questionnaires collected, of which there were 116 valid questionnaires (effective sample rate of 88%). The recruited patients’ average age was 46.4 years, 78 were female.Using the statistical software SPSS 17.0, with bivariate analysis and linear regression analysis to test the relationship between various variables and quality of life. The results reveal that the different degrees of anxiety were the main factor affecting the quality of life, the higher anxiety’s score was, the worse quality of life became. Stratified analyses showed that the different degrees of depression affected the quality of life in the oldest group. But the samples served as volunteer’s cadres in MG club had positive effect on quality of life. Mood disorder is the most common co-morbidity in MG patients. In the treatment of myasthenia gravis, mental health should be actively maintained. MG club had a function to enhance the quality of life of patients; it had been verified in the oldest group of patients. It is recommended that more patients be encouraged to attend the training courses of volunteer cadres. It will help the patients convert the sick role to become an active person of delivering care for other patients. Therefore the quality-of-life of patients will be improved. Clinically, in order to understand the quality of life and psychological status of patients with MG, it is recommended to conduct a comprehensive investigation of quality-of-life scale and Hospital Anxiety Depression Scale. Early intervention will be provided to patients with anxiety or depression so as to maintain their quality-of-life.