Information, knowledge, and skills needs are never static, always changing and evolving. Thus, students are required to master the capability as a lifelong learners of self-directed learning skills (SDL). The purpose of this study is to describe the level of students' SDL skills, the factors that are related and affect the skills of SDL high school students majoring in MIPA. Descriptive research carried out refers to the steps of research Loeb et al. The research step is carried out only until the fifth stage, namely: (1) identifying a phenomenon; (2) consider features of the most prominent phenomena; (3) identifying the construction or preparing the research plan; (4) determine the observable patterns in the data; and (5) communicate patterns in the data describing the reality of phenomena. The results showed that the student's SDL skills were categorized with a tendency at moderate to upper levels. The lowest SDL student skill score was 53 out of a total score 220. Awareness factors, learning strategies, and evaluations are strongly correlated with SDL skills. While the factors of learning and interpersonal skills are highly correlated with the SDL skills. Outside learning factors such as grade, school, gender, and age levels have an effect of 4.3% on SDL skills. The results of this study can be used as a reference of teachers and researchers who need information about the student's SDL skills and related factors.   Abstrak: Informasi, pengetahuan, dan kebutuhan terhadap keterampilan tidak pernah bersifat statis, selalu mengalami perubahan dan perkembangan.Dengan demikian, siswa dituntut untuk menguasai kapabilitas sebagai pembelajar seumur hidup yaitu keterampilanself-directed learning (SDL).Tujuan penelitian ini adalahmendeskripsikan tingkat keterampilan SDL siswa serta faktor-faktor yang berhubungan dan berpengaruh terhadap keterampilan SDL siswa SMA jurusan MIPA.Penelitian deskriptif yang dilaksanakan mengacu pada langkah-langkah penelitian Loeb dkk. Langkah penelitian hanya dilaksanakan hingga pada tahap lima, yaitu:  (1) mengidentifikasi suatu fenomena; (2) mempertimbangkan fitur dari fenomena yang paling menonjol; (3) mengidentifikasi konstruksi atau menyusun perencanaan penelitian; (4) menentukan pola yang dapat diamati dalam data; dan (5) mengkomunikasikan pola dalam data yang menggambarkan realitas fenomena.Hasil penelitian menunjukkan bahwa keterampilan SDL siswa tergolong beragam dengan kecenderungan pada tingkat moderat ke atas.Skor keterampilan SDL siswa terendah adalah 53 dari skor total 220. Faktor kesadaran, strategi belajar, dan evaluasi berkorelasi kuat dengan keterampilan SDL.Sedangkan faktor kegiatan belajar dan kemampuan interpersonal berkorelasi sangat kuat dengan keterampilan SDL.Faktor di luar belajar seperti tingkat kelas, sekolah, jenis kelamin, dan usia berpengaruh sebesar 4.3% terhadap keterampilan SDL.Hasil penelitian ini dapat digunakan sebagai referensi guru maupun peneliti yang membutuhkan informasi mengenai keterampilan SDL siswa dan faktor-faktor terkait.

This study aims to develop a valid and reliable self-rating scale instrument for measuring Self-Directed Learning (SDL) skills. This DDI study follows the steps of Hinkin's development (1995) which consists of five stages: creating an item pool, expert conclusion, implementation, confirmatory factor analysis, and reliability analysis. The self-rating scale developed in this study consisted of sixty statements accompanied by a 1-5 Likert scale. Based on the factors analysis, 16 items were still in the draft and 44 items were declared valid and reliable. Five factors that are determined are: awareness (8 items, α = 0.717), learning strategies (9 items, α = 0.806), and learning activities (7 items, α = 0.777), evaluation (8 items, α = 0.790), and interpersonal skills (12 items, α = 0.907). The reliability coefficient (Cronbach Alpha) of the self-rating scale is α = 0.933, with the required reliability criteria is 0.5. On a scale conversion of 1-100, the student's highest score of SDL skills is 93, and the lowest score SDL skills are 31 (SD = 20.334).