Lina Fuadati. 2016002004. A Syntactic Analysis of Sentence Patterns of the Texts of the Twelfth-Grade Students’ English Textbook for Senior High Schools. A Thesis: English Education Department, Faculty of Teacher Training and Education, Sarjanawiyata Tamansiswa University Yogyakarta, 2020. Sentence pattern becomes important since it affects to the meaning of the sentence. This study dealt with a syntactic analysis that aimed to identify the sentence patterns and to find out the most dominant sentence pattern in the selected texts of the twelfth-grade students’ English textbook. It was conducted by applying mixed method research. Qualitative approach used to describe the sentence patterns and quantitave approach used to find the most dominant sentence pattern. The data were taken from the six selected texts in a textbook entitled Bahasa Inggris for the twelfth-grade students. The process of data analysis was done by reading the whole data, classifying the data based on the sentence types, parsing the data through the tree diagram, categorizing the data based on the sentence patterns, and measuring the percentage of the sentence patterns. Based on the analysis,the result showed that the total amount of the data were 62 sentences and it was found four types of sentence used in the selected texts of the English textbook for the twelfth-grade students in senior high schools. Those types of sentence namely simple sentence (33 data), compound sentence (6 data), complex sentence (19 data), and compound-complex sentence (4 data). Besides, there were also 15 different sentence patterns and the most dominant syntactic pattern was the pattern of S ? NP + VP (37%). Thus, this study suggests that the English teachers need to explain about the sentence pattern to help students in understanding a text.