This study estimated the effect of fermented persimmon (Diospros kaki L.) extract (FPE) supplement on feed intake, digestibility, nitrogen (N) balance, and rumen fermentation characteristics in sheep. Five male sheep (Corriedale${ imes}$Polwarth) with average body weight of $48.6{pm}1.3;kg$ were housed in metabolism crates and assigned to a 5${ imes}$5 Latin square design with five consecutive 20-d periods which consisted of 14-d adaptation and 6-d data collection. The sheep were fed ad libitum a diet containing concentrate and rice straw (3:7). The five treatments were FPE supplemented at 0 (Control), 5, 10, 20, and 30 g/kg of concentrate. Intakes of dry matter (DM, p<0.01), organic matter (OM, p<0.01), neutral detergent fiber (NDF, p<0.05), acid detergent fiber (ADF, p<0.05), and nitrogen-free extract (NFE, p<0.01) increased quadratically with increasing intake of FPE supplement and maximized (p<0.05) at 10 g/kg FPE. The digestibilities of DM (p<0.05), OM (p<0.05), crude protein (p<0.01), and NFE (p<0.01) increased quadratically with increasing amount of FPE supplement, and sheep fed 5 and 10 g/kg diets had greater (p<0.05) DM, OM, and NFE digestibilites than the Control treatment. By increasing FPE supplement concentration, N intake (p<0.01) and fecal N (p<0.05) increased linearly, whereas retained N (p<0.05) and retained N ratio (p<0.05) increased quadratically. The retained N was maximized (p<0.05) in sheep fed 5 and 10 g/kg diets. The mean rumen pH was not affected by FPE supplement, but there was a quadratic increase (p<0.05) of mean rumen ammonia N concentration and a linear increase (p<0.01) in mean rumen total volatile fatty acid (VFA) and acetate concentrations. The mean concentration of rumen propionate in sheep fed all FPE supplemented diets was greater (p<0.05) than the Control, but the mean ratios of rumen acetate to propionate in sheep fed 5 and 10 g/kg diets were lower (p<0.05) than that of Control sheep. In conclusion, FPE supplemented at 5-10 g/kg of concentrate improved feed intake, the digestibilites of OM and NFE, N metabolism, and rumen fermentation indices of sheep.