This study practically examined, with a focus on gender differences, the effects of science classes promoting active learning on junior high school students’ motivation for experimentation and experimental strategies. First, we designed a science lesson that incorporates active learning by using the “Force and Effect” unit of junior high school science as a case study. We then conducted the lesson with 57 first-year students at a public junior high school. The results suggested that among boys, the use of the understanding-oriented strategy and the repeat strategy was encouraged. Furthermore, the understanding-oriented strategy was encouraged more among boys when there was increased utility value.