The objectives of this study were to inquire the theories associated with YLD (Youth Leadership Development), and to draw implications for improving youth leadership abilities, The results of the inquiry revealed the theories associated with YLD as follows; 1. All youth have leadership potential and abilities, but there were few programs to improve it. 2. Activity-Observation-Reflection model of Hughes, Ginnett & Curphy(1993) and Awareness-Interaction-Mastery model of Linden & Fertman(1998) were the best effective YLD models. 3. Situational contingency approach was very appropriate theory associated with YLD. 4. The learning of leadership skills had occurred within an educational context known as experiential learning, so it was the best method of YLD.