In this study, the optimization of the major factors for efficient dilute acid pretreatment (DAP) of Korean barley straw was conducted by response surface method (RSM). In addition, saccharification of the optimized pretreated barley straw as well as fermentation of solubilized hemicellulose and enzymatic hydrolysates was performed for bioethanol production. The factors optimized by RSM were concentration of sulfuric acid, reaction time and temperature. Optimization experiments were carried out within the scope of 0.16 ~ 1.84% sulfuric acid, 10 ~ 20 min of reaction time, and $116{sim}183^{circ}C$ of temperature using a statistical program, and optimal conditions (1.16% of sulfuric acid, 16.9 min of reaction time, and $150^{circ}C$) were determined based on reliable statistical indicators. The predicted value at stationary point and the experimental value were 81.38 and 80.66%, respectively. Saccharification was performed at $50^{circ}C$ using Celluclast (cellulase) and Novozyme 188 (${eta}$-glucosidase) as biocatalysts in an enzyme loading test. Conversion of the saccharification process was approximately 65%. In addition, fermentation of glucose after saccharification and solubilization of xylose solution by DAP were performed using Saccharomyces cerevisiae and Pichia stipitis at $30^{circ}C$ and 200 rpm for 12 h.