This study aims to figure out the intensity of using smartphone, to describe the Grade X students’ learning activities in SMA Muhammadiyah 7 Yogyakarta, and to prove the effect of using smartphone on the Grade X students’ learning activities in SMA Muhammadiyah 7 Yogyakarta. This study was a quantitative descriptive research with correlational model. The population was 150 with 30 students taken as random sampling. The data was collected by using questionnaire, followed by descriptive analysis, anova testing, simple regression testing and hypothesis testing. Result shows that: 1) the level of smartphone usage of Grade X students of SMA Muhammadiyah 7 Yogyakarta is classified as interval 42-46, with total number of 12 students and 40 % intensity. Meanwhile, table 4.0 shows that the mean value is classified as interval 40-43. It proves that the intensity of smartphone usage is categorized as medium. (2) The level of learning activity of Grade X students of SMA Muhammadiyah 7 Yogyakarta is classified as interval 50-53, with total number of 10 students, 33% frequency. Meanwhile, Table 4.10 shows that the mean value is classified as interval 54-57. It proves that the students’ learning activity is categorized as low. (3) There is a significant effect between the variable of smartphone usage and the Grade X students’ learning activities in SMA Muhammadiyah 7 Yogyakarta. It can be seen from the anova test result that shows 0,045 < 0,05. Therefore, it can be concluded that the hypothesis (Ha) is accepted.