<![CDATA[Learning is a basic process of human development. By learning, humans make changes so that their behavior develops. Learning is not just an experience, but learning is a process and not a result. In learning activities at school, educators are faced with a number of very diverse student characteristics. The learning difficulties found at SMA Muhammadiyah 3 Yogyakarta were found to be the average class score in biology subjects was still below the KKM. The purpose of this study was to determine the internal and external factors that cause students to experience learning difficulties and to determine the level of difficulty in learning biology in understanding virus material. This type of research is descriptive quantitative. The population used in this study was 152 with a sample of 79 students. This research was conducted on June 6-7, 2024. This study used a cluster sampling technique because the data sources used were very broad. Data collection techniques used questionnaires and interviews. Data collection instruments used questionnaires and interview guidelines. The data analysis technique for this study used descriptive quantitative analysis.The results of the study showed that the internal factors that caused students in class X (E2, E4 and E4) to have difficulty learning biology on the virus material were physiological factors in the moderate category, with a percentage of 48%, 49.11% and 50%. External factors that caused students in class X-E2 to have difficulty learning biology on the virus material were school factors with a percentage of 74% in the high category, for class X-E4 were school factors with a percentage of 75% in the high category and for class X-E5 were family factors with a percentage of 76.78% in the high category. The biology sub-materials that were considered difficult on viruses were types of viruses and the life cycle of viruses]]>
