Abstrak ZnO nanorods telah disintesis menggunakan teknik hidrotermal pada suhu 95 â°C selama 2 jam. Studi komposisi ZnO nanorods dilakukan menggunakan energy dispersive sinar-x (EDS). Hasil pengujian memberikan konfirmasi bahwa komposisi massa Zn lebih banyak dibandingkan komposisi massa O yaitu 69,44% dan 30,56%. Pengujian sifat optik ZnO nanorods menggunakan spektrofotometer UV-Vis memberikan informasi bahwa terdapat absorbansi tinggi di rentang panjang gelombang ultra-violet (UV) yaitu 360-390 nm. dan absorbansi yang lebar di rentang panjang gelombang cahaya tampak. Kata-kata kunci: ZnO nanorods, komposisi, absorbansi, band gap energy Abstract ZnO nanorods have been synthesized by hydrothermal method at 95 °C for 2 hours. The study composition of ZnO nanorods was performed using energy dispersive x-ray (EDS). The results confirm that elemental mass compositions of Zn and O are 69,44% and 30,56%. The optical properties of ZnO nanorods which investigated by using the UV-Vis spectrophotometer confirmed that the strong absorbance is in the range of UV wavelength (360-390 nm), and wide absorbances in the wavelength range of visible light. Keywords: ZnO nanorods, compositions, absorbance, band gap energy