This study was conducted to investigate the effects of chlorella powder on quality characteristics of maejakgwa (a Korean traditional cookies). Maejakgwa was prepared with different amounts of chlorella powder (in ratios 0, 1, 2, 3, and 4% of flour quantity). The moisture, crude ash, crude protein, and crude lipid contents of used chlorella powder were 2.38, 7.25, 65.95, and 0.95% respectively. The pH of maejakgwa dough decreased significantly as the level of chlorella powder increased; however, density of the batter, spread factor values, and moisture contents of the groups increased significantly with higher level of the chlorella powder. In addition, Hunter’s color L, a, and b values decreased significantly with increasing amounts of chlorella powder. In the texture meter test, hardness increased according to increasing concentration of chlorella powder. Finally, maejakgwas containing 1~2% chlorella powder had the highest sensory evaluation. From these results, we suggest that chlorella powder is a good ingredient for increasing consumer acceptability as well as functionality of maejakgwas.