In this study of the simultaneous saccharification and fermentation (SSF) of paper sludge, fed-batch cultivation of Lactobacillus paracasei subsp. paracasei KLB58 was attempted to produce viable KLB58 cells and lactic acid. Optimal culture conditions, including the temperature and concentration of the supplemented enzyme, were examined in terms of lactic acid production and viable cell count. When the effects of culture temperature and $eta$-glucosidase concentration were examined in fed-batch SSF, the highest viable cell counts and lactic acid production (i.e. 5$ imes$$10^9$ CFU/ml and 45 g/L, respectively) were obtained at 37$^{circ}C$ and 2 unit/ml of $eta$-glucosidase.