In this study, white bread was prepared with Shinan seomcho powder (SSP). Different amounts of SSP were tested (2, 4, 6 and 8%) to determine the optimal amount. The samples and a control were compared for quality characteristics, including pH, total titratable acidity, specific volume, baking loss, moisture content, water activity, color, textural characteristics, external and internal surface appearances, and sensory qualities. As the SSP increased, the total titratable acidity of the dough decreased (pH increased), and a decreased specific volume and baking loss was observed as well. However, the total titratable acidity and pH of the bread did not show significant differences among the samples. The moisture content was highest at a substitution level of 8%, and increased with increasing SSP contents. The crumb L value, a value, and resilience decreased with increasing SSP, whereas the crumb b value and hardness increased. Color, flavor, softness and overall acceptability were highest for the control group and were lowest for the 8% group. This likely reflects the high value of a grassy flavor, green tea taste, bitterness, astringency, and off-flavor at addition level of 8%. As a results, the optimum amount of SSP to add for baking bread would be 2~4%.