The aim of this study was investigation and comparison of relationship between big five factor, happiness and sport achievement in national team, professional and non- professional athletics of eastern Azerbaijan. 72 athletics (Consisting 21 national team athletics, 25 professional athletics and 26 non- professional athletics) who were selected using the access sampling method, were assessed using Big Five Factor Inventory (FFI) (Costa & McCrae, 1992), Happiness Scale (Argyle, 2000) and Sport Achievement (Besharat, 1381). The results were analyzed through Pearson correlation quotient, regression, ANOVA and the follow-up test. Results showed that non- professional athletics, the amount of neuroticism was significantly less than national team and professional athletics (P<1%). The amount of extraversion, happiness and openness was significantly higher than national team athletics compared to other groups (P<1%); also, results showed that the amount of agreeableness and conscientiousness was significantly higher than national team athletics compared to other groups (P<1%). Results showed that in national team athletics and professional athletics there were negative significant correlation between sport achievement and neuroticism (P<5%); also, there were positive significant correlation between extraversion, agreeableness, conscientiousness, openness and happiness factors and sport achievement factor (P<1%). Data analysis through simultaneous regression showed that from among the 6 factors under study in national team athletics and professional athletics, sport achievement can be predicted only by agreeableness and.