The objective of this research is to find out that the use of Clustering Strategy can improve the the ability of the seventh grade students of SMP Negeri 1 Sindue Tombusabora in writing simple descriptive paragraphs. This research applied true-experimental research design which involved two sample groups. There were an experimental group and a control group. The population of this research was the seventh grade students of SMP Negeri 1 Sindue Tombusabora and the sample consisted of four classes: VII A, VII B, VII C, and VII D. The sample was selected by using random sampling technique In collecting data, the researcher used one instrument, namely test. The pre-test was used to measure the students’ ability in writing simple descriptive paragraphs before treatment and post-test was used to measure the students’ ability after the treatment. The data were analyzed by using a statistical analysis in order to know the significant difference of the students’ achievement both in pre-test and post-test. The result of data analysis showed that the t-counted value (9.9) was greater than the t-table value (2.026) by applying 0.05 level of significance and the degree of freedom (df) was 38 (df= 20 + 20 – 2= 38). In conclusion, the use of clustering strategy can improve the ability of seventh grade students of SMP Negeri 1 Sindue Tombusabora in writing simple descriptive paragraphs. Keywords:Clustering Strategy, Descriptive Paragraph, Writing Ability.