A guided inquiry model is able to facilitate students to actively engage in discovering their own knowledge in learning, thereby it enhances the scientific reasoning skills of learners. This research aims to describe the influence of guided inquiry model on the vibration and wave material to the scientific reasoning ability of class VIII students in SMPN 1 Malang. This study uses mixed method type embedded experiments. The data were obtained from pretests and posttest values as well as observation results during the learning process. The quantitative data analysis using value skewness, paired sample t-test, N-gain value, and d-effect size. The qualitative data analysis is based on a description of the learning process through students’ worksheets and interview results. The results showed that the guided inquiry model provides positive effect on the scientific reasoning ability of the junior high school students in class VIII on the chapter of vibration and wave. Different tests with paired sample t-test showed significant difference between pretests and posttest values. Average N-gain of 0.808 with high category and d-effect size of 3.556 with very high category.