The research was conducted to know biology senior high school teachers’ability in planning and establishing assessment instrument in Pringsewu. The research design was simple descriptive design. The research involved 15 biology senior high school teachers. Data were collected in qualitative and quantitative data then they were analyzed descriptively. The results showed that (1) biology senior high school teachers had “high” ability on planning of assessment instrument, (2) biology senior high school teacher had “high” ability on establishing of assessment instrument, and (3) biology senior high school teacher had “low” ability on question item construction.Penelitian ini dilakukan untuk mengetahui kemampuan guru biologi SMA Negeri di Kabupeten Pringsewu dalam merencanakan dan menyusun perangkat penilaian. Desain penelitian yang digunakan adalah desain deskriptif sederhana. Penelitian ini melibatkan 15 guru biologi SMA. Data dikumpulkan dalam bentuk data kualitatif dan data kuantitatif kemudian dianalisis secara deskriptif. Hasil penelitian menunjukkan bahwa (1) Guru biologi SMAN Kabupaten Pringsewu dalam merencanakan instrumen penilaian memiliki kategori “tinggi”, (2) Guru biologi SMAN Kabupaten Pringsewu dalam menyusun instrumen penilaian memiliki kategori “tinggi”, dan (3) Guru biologi SMAN Kabupaten Pringsewu memiliki kemampuan “rendah” pada aspek konstruksi butir soal.Kata kunci : guru biologi, konstruksi soal, perangkat penilaian