The integrated curriculum can promote the application of knowledge and strengthen the connection between traditional classroom teaching and the real world. The organ-system-based integration of basic medicine and clinical medicine has been applied in medical education. This study took all students in class 2020 of the 4+4 M.D. program in Peking Union Medical College who completed the first-year organ-system-function (OSF) integrated modular courses as the example, and expounded the teaching design and teaching process in the integrated course during the basic medical learning. Teaching effect was investigated by questionnaires and interviews with students' satisfaction. The results shown that 70.0% of the modules were well-received with the satisfaction score of more than 3 points, and students were generally satisfied with the OSF integrated courses and the corresponding teaching methods. With the expansion of the 4+4 M.D. program, the design and implementation effects of OSF integration courses will be further explored in the future.