The purpose of this study is to enhance instructional competency of pre-service special education teachers for instructional adaptations, improving the access to the general education curriculum and the curriculum integration of students with disabilities. Accordingly, this study aimed to analyze the contents of lesson plans designed by applying the instructional adaptations of pre-service teachers for an elementary student with special needs who was educated in a inclusive social studies class. Also, the changes of teacher efficacy of pre-service teachers were analyzed. As results, first, there were different frequencies of implementations for the five areas of instructional adaptations, but all of the pre-service teachers implemented instructional modifications in the areas of instructional environment, grouping, instructional methods, and instructional contents. Second, the examples of the learning goals, instructional methods, and evaluation methods were provided in their modified lesson plans with the assignment sheets for implementing instructional adaptations. Lastly, the differences between pre- and post- teacher efficacy for both individual and general efficacy domains were statistically significant. Based on study findings, implications for future research were discussed.