In this study, the quality characteristics of cookies with the addition of Spergularia marina Griseb powder (SMGP) were investigated and analyzed by through chemical and sensory evaluation. Cookies were prepared with different levels of SMGP (0, 1, 3, and 9%). Their moisture and crude protein contents decreased after the addition of SMGP, as did their spread factor (p<0.05). Their Hunter's color L and a values significantly decreased with the increase in SMGP level, whereas their b value increased (p<0.05). In the texture analysis, the hardness of the cookies increased according to the increase in concentration of SMGP and showed a significantly high level in the cookies with the addition of 9% SMGP (p<0.05). In the sensory evaluation, the cookies with the addition of 3% and 9% of SMGP had the highest scores in flavor, taste, and texture (p<0.05). The cookies with 3% SMGP addition had the best score in total acceptability. This study suggests that SMGP is a good ingredient for improving the acceptability and functionality of cookies.