The goal of this study is to analyze the discourses about statistics that occur in classrooms during mathematics lesson in the scope of mathematical language. Case study is used in this study as a qualitative research method. Sample of this study is consisted of seven secondary school mathematics teachers and their students. In order to determine the mathematical discourses about mathematical language, observation method is used as data collection tool. On the other hand, classroom mathematics discourse about statistics is recorded and data of the research are collected. In order to support these video records, field notes are kept in every class about data collection subject area. After turning videos into written documents, they are analyzed in the frame of determined discourse analysis. At the end of the research, discourse types that form the mathematical language are determined to be; defining, understanding visual statements, forming problem, determining strategy in problem solving and reaching result in problem solving. Moreover, the discourses in the mathematical language are examined, it is seen that different types of discourse such as Teacher, Teacher-Class, Teacher-Student, Student-Student are formed according to the interaction in the class. In the light of the research findings, suggestions about mathematical discourses that form the mathematical language and about discussion environments are made. Keywords: Mathematical language, mathematical discourse, statistics learning domain See Extended Abstract