Textbook is one of the educational materials used in English language teaching in the classroom. There are numerous kinds of text in English textbooks, and one of those is descriptive text. In addition, English teachers usually teach students how to understand the sentence by grammar which does not help students comprehend the meaning. Semantic roles can help students in order to comprehend the meaning of sentences. The research aims are to analyze the types of semantic roles and find out the most dominant in descriptive texts in the textbook “Bahasa Inggris SMA/MA/SMK/MAK Kelas X” that was released by the Ministry of Education and Culture based on Saeed’s theory.

The study is qualitative research and content analysis method. The research objects are two descriptive texts in the textbook “Bahasa Inggris SMA/MA/SMK/MAK Kelas X.” The total data in this textbook was 42 sentences. The study used a human instrument and an observation sheet. The researcher used documentation in order to collect the data and used Miles and Huberman’s qualitative analysis to analyze the data.

The research results revealed that there are nine kinds of semantic roles contained descriptive texts. They are agent, patient, theme, experiencer, beneficiary, instrument, location, goal, and source. From those data, the most dominant type of semantic role is theme which appeared in 28 data.