This research aims to reveal the character development of Aang in the cartoon series Avatar: The Last Air Bender by Bryan Konietzko and Michael Dante DiMartino which was firstly launched in 2007. The data source of this research is the footages of the cartoon series Avatar: The Last Airbender. The research method for this research is using the Theory of Human Motivation by Abraham Maslow; to identify the character development of Aang by referring to Abraham Maslow’s hierarchy of needs. Those needs are: physiological needs, safety needs, love needs, self-esteem needs and self-actualization need. The result of the discussion reveals that there is a character development that is shown by Aang in the cartoon series Avatar: The Last Airbender after the fulfillment of those needs by Aang. At first, Aang is just a usual kid with only a few of ability. As he is going on his journey, the fulfillment of his physiological, safety, love, self-esteem and self-actualization leads him becoming a self-actualized person by becoming a true avatar. He also becomes a forgiving and democratic person, which is the characteristic of self-actualized person.