The present paper by using a descriptive-analytic method aims to study the impact of believing in Imam Mahdi (pbuh) on the perfection of individual ethics in the light of the statements of the supreme leader of the Islamic revolution, Imam Khamenei (may Allah prolong his life). To believe in Mahdism has increasing psychological and physical positive effects on the believers and guards them against the external and internal corruption in the universe. The result of this study is that based on the sayings of Ᾱyat Allah Khamenei, creating and strengthening a religious world-view and seeking nearness to Allah, and making a firm belief in the Imam and an unbreakable connection with him are among the consequences of believing in Mahdism in the field of the development of individual epistemological ethics. Some of the examples of this impact on practical and behavioral development are such as self-refinement, being hopeful for a bright future, fighting against hopelessness, patience and resistance in confrontation with woes and miseries for a better future, creating a double attempt and more growth and vitality in the path of individual life, creating the stance of commitment and responsibility in the individual, dissatisfaction with the current situation and seeking to gain the desired situation and feeling of pacification.