On the 18th -24th of August, an online international summer school was held between Shanghai University of Medicine & Health Sciences, Khon Kaen University, Chulalongkorn University, and FHU (Faculty of Radiological Technology). This is the third year of this online summer school, and 31 students participated in the event. On the first day, participants introduced themselves using the slides and interacted with each other through games. From the second day, participants tried to expose themself to English in various ways, such as attending English lectures and introducing the participants' universities and countries. This year they had a special lecture, “Application of virtual reality to the medical radiation field” by Dr. Toshio Fujibuchi of Kyushu University. After the lecture, participants actively asked questions even though some of them were not good at English. On the last day, each group presented what they had learned in the lecture. In the group work, the participants communicated not only by discussions but also using chat tools.　The survey conducted afterward showed that many of them had a fruitful time.