Sago bark biomass waste was modified into biochar through pyrolysis with temperature variations of 500 ℃, 600 ℃ and 700 ℃ for 2 hours to increase the adsorption capability. This research aims is to know the adsorption isotherm model of methylene blue on sago bark biochar. The results showed that the adsorption capability of biochar increased comparing to the adsorption capability sago bark without pyrolysis process dan reached optimum adsorption condition at pH 9 for 10 minutes. The results of the analysis show that the adsorption of methylene blue on biochar is closer to the Freundlich isotherms model than to the Langmuir isotherm model. The adsorption capacity of methylene blue on pyrolysis biochar at temperature of 500 ℃, 600 ℃, and 700 ℃ respectively were 45,86; 46,22 and 46,90 mg/g.Abstrak: Limbah biomassa kulit sagu dimodifikasi menjadi biochar melalui pirolisis dengan variasi suhu 500 ℃, 600 ℃, dan 700 ℃ selama 2 jam untuk memperbaiki kemampuan adsorpsinya. Penelitian ini bertujuan untuk mengetahui pola isoterm adsorpsi metilen biru pada biochar kulit sagu. Hasil penelitian menunjukkan bahwa kemampuan adsorpsi biochar terhadap metilen biru meningkat dibandingkan adsorpsi sebelum proses pirolisis dan mencapai kondisi optimum adsorpsi pada pH 9 selama 10 menit. Hasil analisis menunjukkan bahwa adsorpsi metilen biru pada biochar lebih mendekati model isoterm Freundlich dibanding model isoterm Langmuir. Kapasitas adsorpsi metilen biru pada biochar hasil pirolisis pada suhu 500 ℃, 600 ℃, dan 700 ℃ berturut-turut sebesar 45,86; 46,22 dan 46,90 mg/g.