The importance of curriculum inclusion that can meet the special educational needs of all students increases, Universal Design for Learning(UDL) is emerging as an effective way to realize curriculum inclusion. However, compared to the weight of the philosophy and theoretical legitimacy of UDL, it is difficult to settle in the educational field, and the teachers who implement the UDL are confused due to the lack of specificity in implementation. Therefore, this study presented references and suggestions for UDL’s establishment in the educational field by analyzing 20 lesson plans that applied UDL. According to the results of this study, first, lesson plans were mainly conducted to improve the academic achievement of inclusive elementary school students including students with developmental disabilities. Most of lesson plans presented differentiated learning goals for students, applied activity-based teaching and learning elements, and used technology as a learning guide tool. Second, six key words and corresponding details were extracted from the representation and expression principles, respectively, and nine key words and corresponding details were extracted from the engagement principle. Third, satisfaction rates for the principles of representation, expression and engagement were applied evenly, while the satisfaction rates for each guideline were unbalanced. Based on the results, discussion and suggestions for the application of UDL to the educational field were presented.