Character development is a psychological condition that everyone can experience; in the Black Swan film, Nina Sayers is one of them who experiences character development. In this research, the researcher focuses on describing character development and the factors that influence the character development of the main character in the Black Swan film. The researcher uses two theories to answer the two problem formulations. In the first question, the researcher used Murphy's characterization theory to find out the character of Nina Sayers in the Black Swan film before and after changing. In the second question, the researcher used the personality development theory of Elizabeth B. Hurlock to find out the factors that influence the character development experienced by the main character. In this research, the method that the researcher used was the qualitative descriptive research method. The analysis results show that Nina's character has changed from submissive to disobedient, innocent to rebel, kind to revolt, quiet to rude, and weak to brutal. The developments of these five Nina's character are influenced by three determinants such as emotional, aspiration and achievement, and family.