This research is an example of research with the type of classroom action carried out by field study teachers based on observing the problems contained in the classroom. This study aims to improve student learning outcomes, especially Indonesian language subjects on the topic of writing biographical texts. This study applies learning media, namely the YouTube application as a supporting medium for the learning process in class. This research was conducted in class X TEI I, totaling 27 people. Consisting of 19 women and 10 men. Data collection in this study was carried out by making observations, written tests in each cycle that were carried out, and viewing documentation in the form of exposure to student learning outcomes on biographical text writing materials prior to the application of learning media, namely the YouTube application, with an average student learning outcome for each cycle after using learning media in the form of using the YouTube application. The technique used in analyzing the data is descriptive qualitative technique. The results of the analysis of the data obtained in this study (1) the use of learning media, namely the YouTube application according to the age category and the chapters studied by students of class X TEI I (2) In the first meeting there were 7 people who succeeded in writing biographical texts correctly, In the second meeting there were 11 people who succeeded in writing biographical texts correctly and in the second meeting there were 25 people who wrote biographical texts correctly.