Writing is an important skill in English material which must be mastered by all students especially for junior high school. SMP Negeri 23 Semarang is one of school chosen for being a research. The research in that school focused on mastering descriptive text as one of writing material. The students can not master well descriptive text because the teacher still use conventional method in learning activities. Therefore, the teacher should have a new alternative approach to teach writing of descriptive text. One of alternative approach is SAVI approach that can be applied in teaching learning. The researcher aimed to elaborate classroom action research as one of research types used in this research. It could be realized by a teacher in which involved a group of students to improve the teaching learning process, especially in writing skill. The researcher used quantitative form to analyze the data. The data was collected from documentation, observation, and test. Documentation such as students name list, students English score, and lesson schedule.. Observation was aimed to see and know the condition of class and students during learning process. Test was used to know students achievement, so the researcher can know the students improvement and achievement in mastering descriptive text. The approach used by the researcher in this study is SAVI approach that belong’s to Dave Meier. The results of this study indicate that SAVI approach can improve the students writing skill of descriptive text at VII grade students of SMP Negeri 23 Semarang in the academic year of 2015/2016 based on the result of the research was done two cycles (cycle 1 and cycle 2). It can be taken the conclusions that there was good significance. The students writing skill of descriptive text improved after being taught by using SAVI approach. The implementation of SAVI approach as a learning aid to improve the students writing skill of descriptive text was very effective. It was supported by significance result of the students average in pre-cycle was 64.3 and observation checklist students’ got 52% because the students’ still confused about the material. In cycle 1 began used SAVI approach to improve students writing skill of descriptive text got average was 72.64 and observation checklist students’ got 72%. In the cycle 2, the students’ more understood and enthusiastic in learning process and got average was 77.77 and observation checklist students’ got 88%. These proven that the students’ participation in writing descriptive text had improved after taught by using SAVI approach. was 55.83. In the first cycle, the students’ average score was 69.38 and in the second cycle students got 74.