This paper is a report on the findings of a study based on empirical research on mobile learning. We conducted concrete and theoretical research on the modern problem of mobile learning considering the learning environment. Although lifestyle and transportation differ in each country and area, we used an audio-visual test of contents, questionnaire surveys, a performance test in train and room environments and then we had experiment for media comparison. As a result, the questionnaire survey revealed that many learners tended to regard the room environment as suitable for study. On the other hand, a significant main effect was detected in the contents with the caption in the performance test. But, in experiment for media comparison, we don't have main effect for everything. We reflected on the problems of the modern mobile learning study and performed a substantial study of the theory of mobile learning that considers the learning environment.