The key to make English teaching learning activity goes smoothly is teacher’s talk. They are required to employ certain communication strategies to communicate as effective as possible in order to make her students easier to learn English. The objective of this study is to investigate the kinds of communication strategies which are used by an English teacher inan international school in Yogyakarta. This research used qualitative approach. The data were obtained through observation and recording 60 minutes of English lesson. The source of the data was communication strategies which were used by an English teacher in interacting with her tenth graders. The subject of this study is an English teacher of an international school in Yogyakarta and one of her class, in the academic year of 2017/2018. The researcher used the communication strategies of Celce-Muria et al (1995) as a framework for the data analysis. The result showed that the communication strategies used by the teacher were first Stalling or gaining strategy revealing fillers and gambits and also self and other repetition; second Achievement or compensatory strategy revealing restructing and nonverbal signals; third Self monitoring strategy revealing self initiated repair; and the last interactional strategy revealing appeals for help and meaning negotiation. However, the avoidance or reduction strategy did not appear during the conversation.