The purpose of this study is to investigate the effect of Panoramic Virtual Reality (PVR) applied to online earth science classes on students’ learning flow. To this end, a PVR learning material was made with a geology learning site, which contains a core geologic concept contained in a high school curriculum in Korea. To this end, a PVR learning material was made at a geologic field site to provide an interactive and engaging way for students to grasp core geologic concepts according to the high school curriculum in Korea. The PVR was applied to online earth science classes with 45 high school students. In order to examine the effect of the PVR on students' learning flow, pre-post learning flow test papers were used, then matched-sample t-test analysis and students' responses were analyzed. The result shows online classes with PVR have positive effects on learning flow (p<0.05). And it was possible for the students to observe three-dimensional geologic structures effectively in online classes as in offline field trips. And the students' responded with positive feedbacks. These suggest that PVR in online classes can be used as an effective teaching method, which can improve students' flow and eventually understanding subjects.