Writing is one of the language skills that belongs to MKK (Matakuliah Keilmuan dan Keterampilan) subject. This subject provides the students with basic knowledge and skill. As MKK subject, writing is a compulsory subject for the students of English Department of UTM. Related to the implementation of competency- based curriculum in SMP and SMU, English Department of UTM applies text- based syllabus for writing. However, the students still find difficulties in developing paragraphs. The problems addressed in the research are (1) to what extent can Thematic Progress Patterns with Cooperative Learning Method (TP-CL) improve the students writing skill. (2) to what extent Thematic Progression Patterns with Cooperative Learning Method (TP-CL) is effective forteaching writing; The data used in the research were the paragraphs that were written by the fourth semester Students of English Department of UTM who took writing 3 subject in 2011/2012 Academic Year. To analyze the effectiveness of TP-CL in teaching paragraph writing, the writer followed Blum in Nunan theory (1994) and Constant Comparative method developed by Glaser and Strauss (1999). This method consists of four stages. They are comparing incidents applicable to each category, integrating categories and their properties, delimiting the theory, and writing the theory. Besides that, I also applied simple quantification (descriptive statistics) in this Classroom Action Research in order to show whether or not introducing Thematic Progression patterns with Cooperative Learning Method can improve the students competence in developing the paragraph. Vol. 39 No. 2, 15 Agustus 2013 : 94-116 The result of the research shows that the implementation of TP-CL can make the teaching- learning activity of writing class effective. In addition to that, it was proved that introducing Thematic Progression Patterns can improve the students writing skill. The results suggest that writing lecturers should introduce text- types to the students as well as how to develop the paragraph in order that they can write paragraphs coherently and various Theme in order that they can write the paragraph artistically. In addition to that,the application of various cooperative learning methods can make the teaching- learning process effective Key Words: Thematic Progression, Cooperative Learning Method, Writing, Effective Teaching.