Odia subject has been introduced in secondary level from class 8th to 10th as First language i.e. mother tongue in Odisha. It is a compulsory subject for all students reading in secondary levels. This subject is very much useful to read, write & express our thoughts freely. Various methods are adopted to teach odia subject which has not yet proved to be an appropriate one. Generally teachers in Odia subject use, lecture method, narration cum, discussion, structural approach to teach this subject, where the students feel difficulties in making out the subject thoroughly with these methods of teaching. After research work, a new method of teaching i.e. co-operative learning is used to teach the subject then, it is easier for the students to understand the subject thoroughly. Therefore, it is imperative for the researcher to choose such an appropriate research study on effectiveness of co-operative learning method on Odia subject among the secondary school students. An attempt has been made to study the effectiveness of co-operative learning method among the secondary school students of Odisha.