The aims of this study are to clarify the role of the curriculum experiment in curriculum development, to understand the implantation and methods of different types of the curriculum experiments, and to suggest possible approaches and supports of implementing the curriculum experiments for 12-year National Education Curriculum. The methods employed in this study involve literature and document analysis, and focus group interviews. Through the methods, this research proposes four principles of curriculum experiments - being autonomous, interactive, commonly good, and cumulative and evolving. The mechanism for curriculum experiments on National Curriculum Guidelines as well as further educational issues is also suggested, concerning specific strategies of governmental, local governmental and local school levels.