This research is aimed at improving the students’ writing skill and finding out what extent method of peer correction can improve the students’ achievement in writing explanation text. The subject of this research is the students of class X Science 4 at SMAN 5 Surakarta in the academic year of 2015/ 2016.

The research was carried out in two cycles. Each cycle encompassed planning, acting, observing, and reflecting. The research data were obtained in the form of quantitative data and qualitative data. The quantitative data was collected by conducting pre test and post test for the students. Meanwhile, the qualitative data was collected by conducting observation of the teaching learning process and interview with the teacher and the students.

Before implementing peer correction, the students had problems related to writing aspects namely content, organization, vocabulary, grammar, and mechanic. There were only eight students who succeeded in passing the standart minimum competence which was 67. In addition, the method applied by the teacher could not overcome the writing problems faced by them. The teacher gave inadequate feedback to the students’ writing. Meanwhile, based on the data analyzed, it was found that their writing ability continuously improved in each cycle. This was affected by the implementation of peer correction method. The students’ mean score increased from 64,5 in the pre test, while in post test I was 75,2, and became 82,7 in post test II.Those increases were followed by the improvement of the students’ score on each aspect of writing namely content, organization, vocabulary, grammar, and mechanic. Dealing with content of writing, the score was improved from 21,5 to 23,78 in post test I, and to 25 in post test II and organization aspect increased from 11,9 in pre test to 14,33 in post test I and became 16,9 in post test II. Furthermore, vocabulary mastery was improved from 12,6 in pre test to 14,56 in post test I and 16,06 in post test II. Aspect of grammar was also raising from 15,1 in pre test and became 18,55 in post test I and 20,8 in post test II. Lastly,mechanic aspect of writing improved from 3,45 in pre test, and then it was improved to 3,96 in post test I and 4 in post test II.Moreover, according to the observation in the students’ participation, the implementation of peer correction also influenced the improvement of the effectiveness of teaching learning process. It can be summarized that peer correction can improve the students’ writing ability and the teaching learning process.

Keywords: writing, explanation text, peer correction, classroom action research