The present study investigated the use of convensational implicatures conveyed by the student of English Letters Departement of the Islamic State University of Malang (ELD-ISUM). it employed a qualitatif approach (ethnography) in order to explore the phenomena of the students' conversational implicatures that naturally occur in the clasroom contexts. A class of students was used as the research subjects. The data were obtained from observing classroom interactions on 'speaking' course. The data were simultaneously gathered by means of the observation, recordings and field notes. The analysis of data was carried out by means of the intersactive model. The study revealed that the student realized two types of convensational implicatures, i,e., generalized conversational implicature (GCI) and particularized conversational implicature (PCI) in their interactions. These GCLs and PCLs werw frequently realized by means of the indirect illocutionary forces in the forms of directive and expressive acts. in terms of the GCLs, the students favor three kinds of heuristics,namely, Heuristic-Quantity,Heuristic-Informativeness, and Heuristic-Manner.