This study explores the effectiveness of the 5-step learning cycle model on students understanding related to SHM. 103 students (53 experimental group and 50 in the control group) are taken as sample. The research is an experimental research design that is based on pre and post-test. Students' answers were analyzed based on qualitative and quantitative. First, the student's responses were analyzed by determining the number of students, who possess sound understanding, partial understanding, and alternative ideas of the concepts. According to pre-test and post-test results, it was observed that most of the students shifted their level of understanding from alternative conception to partial or sound understanding. In the second the student is analyzed quantitatively and compared with the students' mean score of the group. It was also found that the students understand most of the concepts except the concept of amplitude and frequency. The 5-e step learning cycle model is better than the conventional method.

Keywords: Five-Step Learning, Harmonic Motion's, SHM, Pre and post-Test.