Recently, many researchers are interested in the game-based learning environment. However, few empirical studies investigated the issues of surrounding influence between real classroom context and virtual environment context. Hence, this study examines the interactions among students in the situation of competitive games. We implemented a game-based learning environment, entitled My-Pet-My-Quest, and a study was conducted in an elementary after-school club for 29 students over a four-month period. This study employed a mixed approach for data collection and analysis that contains collecting system records data, observation comments, and questionnaires, as well as adopting social network analysis and regression analyses. The results showed that 1) the students' self-reported friendship states predict the extent to which they interact with their friend in on-line environment; 2) the interactive patterns of schoolboy and schoolgirl differ regarding their genders in game-based learning environment; and 3) an elementary school student in the competitive game not only competed with others, but also enhanced the social interaction and emotional communication. Some suggestions about the results were also discussed. Firstly, researchers could use mixed methods to explore the patterns of interaction on game-based learning environments; secondly, researchers could adopt social network analysis for the design of game-based learning environments; finally, researchers could comprehend the interactive patterns of real classrooms and virtual competitive games.