This paper reports the exploratory study's finding based on the participants' behaviors while interacting with Augmented Reality based system in group learning environment. Technology has long been used to enhance group learning, often known as Computer-Supported Collaborative Learning (CSCL). Recent research in this area showed that technology somehow hinders the communication and interaction of group members. Therefore, as suggested by many researchers, introducing back the physical interaction could reduce these obstacles. Augmented Reality (AR) is the technology whereby the physical and virtual objects can co-exist in real time. The physical objects can be used to interact with the system. However, literature showed the number of the papers that explore the interaction and communication process which occurred while using AR to support group learning relatively low. Therefore, this paper is aimed to fulfill that gap. Conducting a science experiment on electricity topic was used as a case study. Eight groups of two students participated in this study. The primary data used in this study was collected from the analysis of video recording of students' behavior as well as from the survey questionnaire on the user awareness of communication and interaction. The video were then annotated and coded to extract information by using Actogram2 software. Results showed that several types of natural interactions were exhibited. Both verbal and non-verbal communication cues were observed. Physical objects were the main interacting material that group members referred to and used. These results suggested the importance of incorporating physical objects in collaborative AR based system. Further, this study showed positive evidence to strengthen the raised conjuncture that AR could be one of the effective tools to support collaborative learning. © 2013 The Authors. Published by Elsevier B.V.