The biogas fermentation of vinasse (TS 7.015 +/- 0.007%) was investigated within a wide range of COD (Chemical Oxygen Demand)/N (Total Nitrogen) ratio. Urea (46% nitrogen content) was added into substrate to adjust COD/N ratio of 400/7-700/7. This study used batch anaerobic digesters in laboratory-scale that were operated at room temperature in 60 days. The results showed that control variable, 400/7, 500/7, 600/7, 700/7 generated total biogas of 107.45, 123.87, 133.82, 139.17, 113.27 mL/g COD and had the value of COD removal of 31.274 +/- 0.887, 33.483 +/- 0.266, 36.573 +/- 1.689, 38.088 +/- 0.872, 32.714 0.881%, respectively. Variable with COD/N ratio of 600/7 was the best variable. In the kinetic model of biogas production, variable with COD/N of 600/7 had kinetic constant of A (mL/g COD), (mL/g COD.day), 2 (days) of 132.580, 15.200, 0.213, respectively. The model equation of kinetic of biodegradability organic materials obtained was C(t) = (Co - exp {-exp [mu e/A(lambda - t) + 1]} * Co) + Ce. (C) 2013 Elsevier Ltd. All rights reserved.