The purpose of this study was 1) to figure out the types of illocutionary acts performed by the lecturer during online classroom interaction. 2) to figure out the function of the lecturer's illocutionary acts in online classroom interaction. The descriptive qualitative technique was adopted in this study.The lecturer at Lambung Mangkurat University's English Language Department as the subject of this study. The researcher employed an observation sheet, an interview guideline, and recording to collect data. During the data analysis process, the researcher used data reduction, data display, and finally draws the research’s conclusion. The first result shows the lecturer produced four kinds of illocutionary acts. There are 275 utterances types of illocutionary acts that produced by the lecturer in online classroom interaction. They are 165 directive data, 86 expressive data, 25 representative data, and 1 commissive data. The second result demonstrates three types of illocutionary acts performed by the lecturer during online classroom interaction. The kinds of illocutionary acts function are found by the researcher 250 data. They are 161 competitive data, 86 convivial data, and 3 collaborative data. The lecturer used many questionings in the process of teaching and learning because it allowed the students to participate more actively in class and also suggested that the study of speech acts be expanded, as this study was limited to the lecturer’s utterances.

Keywords: Speech acts, Illocutionary Acts, and Classroom Interaction