This study examined professional development systems in America, England, and Australia, and devised ways to enhance early childhood teachers' professional development in Korea. To suggest effective ways to improve current professional development system and its operation, this research aimed to investigate first, advanced professional development systems and policies in three countries, America, England, and Australia, second, the process of teacher qualification and requirements for acquiring teacher credential and its maintenance, and lastly, the effort of quality control for professional development, its operation, and evaluation systems in three countries. Based on the analysis of the three country’s systems, five solutions for effective professional development are suggested. First, it is necessary to differentiate requirements for teachers by the level of teacher credentials. Second, an incessant training process for professional development is required. Third, an individualized professional development plan should be set for an individual teacher for the best outcomes in professional competence. Fourth, instructors for professional development trainings are needed to ensure the quality of training. Lastly, individuals, organizations, and policy and its operation systems need to be considered holistically as a whole in the perspective of convergence in policy making and its operation for effective professional development.